02032021 Area and Perimeter MATHSWATCH CLIP 52 53

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 L. O. To be able to § Find the perimeter of any polygon § Find the area of rectangles and triangles § Find the area of compound shapes, made of rectangles and triangles § Find the area of trapeziums and parallelograms Key Words polygon, area, perimeter, compound, length, width, height, squared, edge Starter Year 8 I have attached this powerpoint for examples and to support your learning. Follow how to do it and any questions you can email me on wbevis@yphub. org.

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 AREA BY COUNTING SQUARES

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Area – counting squares § AREA measures the amount of 2 D space taken up by a shape § It measures the INSIDE of a flat shape § It is measured in squared units (cm 2, mm 2, km 2, etc) § Each unit looks like a square § So if a shape is made up of small squares, we can just count them to find the area § Each small square is 1 cm 2. The area of this rectangle is 8 cm 2.

02/03/2021 Area and Perimeter Task – find the area of each rectangle 1) 4) 2) 5) 3) 6) MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task – which rug covers a larger surface? Rug A Rug C Rug B

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 AREA OF A RECTANGLE

02/03/2021 Area and Perimeter Rectangles § For any rectangle… AREA = base × height = B × H H B MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Area and Perimeter Example Find the area… 4 cm 8 cm Because it’s a RECTANGLE… AREA = B × H = 8 cm × 4 cm = 32 cm 2 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task – Find the area of each shape 1) 3 cm 2) 6 cm 3) 5) 10 m 4 m 90 mm 7 cm 4) 13 m 2 m 50 mm

02/03/2021 1. a) Area and Perimeter 1 cm b) 4 cm 7 cm c) 9 cm 36 cm 2 7 cm 2 e) 2 cm f) g) 10 cm d) 4 cm 6 cm 2 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 5 cm 1 cm h) 7 cm 5 cm 16 cm 2 8 cm 2. 3. 30 cm 2 3 cm 42 cm 2 A rectangular room measures 4. 5 m by 4 m. What area of carpet is needed to cover the floor? This rectangle has an area of 36 cm What is the length of p? 6 cm 18 m 2 p 4 cm 20 cm 2 9 cm 2 30 cm 2 6 cm

Area and Perimeter 02/03/2021 100 m 1 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 2 50 m 90 feet 4500 ft 2 5 000 m 2 3 50 feet 40 m 4 120 m 18 900 cm 2 4 800 m 2 5 90 cm 8½ cm 210 cm 5½ cm 46. 75 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 AREA OF RECTANGLES On your mini whiteboards… Multiple choice!

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 10 cm 40 cm 2 14 cm 2 40 cm 28 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 13 cm 5 cm 65 cm 2 85 cm 2 75 cm 2 45 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 15 cm 2 cm 17 cm 2 30 cm 2 60 cm 2 34 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 8 cm 12 cm 84 cm 2 88 cm 2 96 cm 2 108 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 11 cm 5 cm 16 cm 2 55 cm 115 cm 2 55 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 15 cm 6 cm 105 cm 2 65 cm 120 cm 2 90 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 18 cm 3 cm 64 cm 2 76 cm 2 54 cm 2 58 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 16 cm 4 cm 62 cm 2 64 cm 2 44 cm 2 84 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 13 cm 4 cm 39 cm 2 42 cm 54 cm 2 52 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 19 cm 5 cm 185 cm 2 85 cm 115 cm 2 95 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 AREA OF A TRIANGLE

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 What proportion of this rectangle has been shaded? 4 cm 8 cm What is the shape of the shaded part? What is the area of this right-angled triangle? 16 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 What proportion of this rectangle has been shaded? 4 cm 8 cm Drawing a line here might help. What is the area of this triangle? 16 cm 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 B H

02/03/2021 Area and Perimeter Example What is the area of this triangle? 6 cm 7 cm = 21 cm 2 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task – Find the area of each triangle 5 m 8 mm 15 mm 3 m 5 mm 4 m 10 mm 5 cm cm 3 cm

Area and Perimeter 02/03/2021 1) 2) 8 24 cm 22 3) 4 14 10 5) 12 cm 2 8 5 17. 5 cm 2 8) 7) 12 4 6) 3 35 cm 2 5 24 cm 22 20 cm 22 6 4) MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 7 4 16 18 cm 2 40 cm 2 5 9 9) 260 cm 2 26 20

Area and Perimeter 02/03/2021 1) 14 9 8 30 cm 2 3) 2) 40 cm 2 12 8 12 5 10 10 11 36 cm 2 6 4) MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 10 6) 5) 16 54 cm 2 12 14 9 14 10 22. 5 cm 2 90 95 1200 cm 2 9 5 30 80

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Spot the errors Mrs Bevis’s solution. . . 5 cm 4 cm 6 cm Question: a) Find the perimeter of the triangle b) Find the area of the triangle a) Perimeter = 5 cm + 4 cm + 6 cm = 15 m b) Area = 2 x 6 cm x 5 cm = 60 cm

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 AREA OF COMPOUND SHAPES

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Skills re-cap § Choose your level of challenge. Complete ONE question. 2 cm 5 m 3 cm 3 m 6 cm 2 cm Work out the perimeter and the area Work out the perimeter

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Compound shapes § Irregular shapes like these are known as compound shapes § There is no area formula for these types of shapes § Instead we need to break them up into manageable pieces… shapes we DO know the area formula for § What shapes are these?

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Compound area § Find any missing sides § Split the shape into manageable pieces § Label these pieces § Find the area of each piece (make sure you use the right formula!) § ADD all the areas up 7 m Split it either like this … … or like this. A 10 m 15 m 7 10 A 8 m B 15 m 15 5 B Label the rectangles A and B. A: 10 × 7 = 70 m 2 B: 5 × 15 = 75 m 2 Total area = 70 + 75 = 145 m 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 REMINDER! Finding missing sides § Highlight all sides that are going in the same direction § The smaller sides should add up to the longest side § Remember dashes indicate two sides are the same length 9 cm a = 12 – 5 cm = 7 cm b = 9 – 4 cm = 5 cm 12 cm 4 cm a cm 7 cm 5 cm b cm

02/03/2021 Area and Perimeter Task – Try to find the area of this shape 2 cm 3 cm 6 cm 2 cm MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Example Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Re-cap! – copy and complete this step-by-step for area of an L-shape § Find the missing ______ § Split into two ______ § Find the two areas using the rectangle formula AREA = _______ § _____ them together § Remember the units for area are always ______

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task § Choose a task you think is right for you from these options Ø Rectangles only Ø L-shapes Ø Compound shapes with triangles in § Find the AREA and PERIMETER of every shape on your sheet § Extension questions are on the strip of stickers on the board… Ø come up and choose a sticker Ø take it and stick it in your book Ø complete that question underneath the sticker § Prizes available for impressive work

02/03/2021 Area and Perimeter 4 a) 2 2 b) 5 7 4 4 5 3 1 2 2 7 d) 3 e) f) 4 5 2 2 4 3 2 1 4 3 4 2 3 c) 2 4 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 1 5 2 6

Area and Perimeter 1) 8 m 2) 4 cm 4) 3 mm 3 m 4 m 6 cm 1 mm 7 cm 3) 10 mm 7 m 9 cm 6 mm 7 mm 02/03/2021 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 8 mm 4 m 3 m 10 m 2 m 7 m 2 m 4 mm

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Spot the errors on my answer to this EXAM QUESTION Area = 10 x 16 = 160 m 3 36 times tables are 36, 72, 108, 144, 180, … So he can fit in 5 pigs because 160 is closer to 180 which is 5 pigs.

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Examples The diagram shows a 6 -sided shape made from a rectangle and a right-angled triangle. The diagram shows a wall with a door in it. 2 cm 7 cm 12 cm 2 x 12 = 24 6 cm 3 x 4 =12 5 (5 x 6)÷ 2 = 15 Work out the total area of the 6 -sided shape. (3) 3 1 x 2=2 Work out the shaded area. ………………m 2 (Total 3 marks)

Area and Perimeter 02/03/2021 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task – Find the SHADED AREAS in these pictures b) 9 cm 7 cm a) 4 cm A 11 cm 8 cm B 6 cm A 3 cm 4 cm B

02/03/2021 Example Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Example Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

Area and Perimeter 02/03/2021 Task – Find the area of each shape 1) 6 m 2 cm 4 cm 8 m 3) MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 7 m 10 cm 2 m 4) 10 mm 8 m 7 mm 2 m 10 m 12 mm

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 AREA OF TRAPEZIUMS AND OTHER QUADRITATERALS

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task – Which of the shapes below are parallelograms and which are trapeziums?

02/03/2021 Area and Perimeter a h b MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

Area and Perimeter 02/03/2021 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Example – Find the area of this trapezium 6 m 9 m 14 m = 90 m 2

02/03/2021 Area and Perimeter Example – Find the area of this trapezium 9 m 4 m 12 m MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task – Find the area of each trapezium 12 cm 1 5 cm 2 6 cm 9 cm 8 cm 4 2 m 4 m 3 3. 9 cm 7 cm 5 7. 1 cm 5 cm 4 m 3 m 10 m

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Parallelograms § For any parallelogram… AREA = base × height = B × H § The base and height you use must be perpendicular height base

02/03/2021 Area and Perimeter MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Example 4. 9 cm 4. 5 cm 7 cm Area of a parallelogram = b × h = 7 × 4. 5 = 31. 5 cm 2 We can ignore this length

Area and Perimeter 02/03/2021 MATHSWATCH CLIP 52, 53, 54, 55, 56 GRADE 2 Task – Find the area of these parallelograms 2 1 2 cm 3 cm 4 cm 3 4 cm 4 3 cm 1 cm 5 cm