Properties of Triangles Classifying Triangles Click on the

Classifying Triangles Click on the link before to watch the video! https: //www. youtube.

Types of Triangles Equilateral Triangle Isosceles triangle Scalene triangle 3 equal sides 2 equal

Any triangle containing a 90 o angle is a right-angled triangle 90 o An

Triangles may be classified by the lengths of their sides. Triangles may also be

The 3 Angles inside a triangle always add up to 1800 This is called

To determine the angle sum of any Triangle Take 3 identical copies of this

Complete this activity to prove that the three angles inside a triangle add up

3 identical copies 1800 The 3 Angles inside a triangle always add up to

Types of Triangles Review 2. 1. 3. Equilateral Triangle Isosceles triangle Scalene triangle 3

Calculating unknown Angles Example 1 65 o Calculate angle a. a You know that

Calculating unknown Angles Example 3 b Angle a = 65 o (base angles of

Calculating unknown Angles 90 o Example 5 Calculate angles a and b. a b

Solve for the missing Angles Go to this interactive site link below. Go to

Complete the Triangle Practice pages on our website. Correct these pages using the answer

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Properties of Triangles

Classifying Triangles Click on the link before to watch the video! https: //www. youtube. com/watch? v=m. Le. Na. Zcy-h. E

Types of Triangles Equilateral Triangle Isosceles triangle Scalene triangle 3 equal sides 2 equal sides 3 unequal sides 3 equal angles. 2 equal angles (base) 3 unequal angles

Any triangle containing a 90 o angle is a right-angled triangle 90 o An isosceles or a scalene triangle may contain a right angle. When you see the box in the corner, you know the angle is 90 o Right-angled isosceles triangles. scalene triangle.

Triangles may be classified by the lengths of their sides. Triangles may also be classified by their angles.

The 3 Angles inside a triangle always add up to 1800 This is called the Angle Sum.

To determine the angle sum of any Triangle Take 3 identical copies of this triangle and put them together, so: How can we use this to help us? 3 1 Angles on a straight line add to 180 o 2 These are the same angles as in the triangle! The angle sum of a triangle = 1800

Complete this activity to prove that the three angles inside a triangle add up to 1800 1. Draw a triangle with a ruler and put a star on all three corners. Cut out the triangle. 3. 2. A straight line is 1800

3 identical copies 1800 The 3 Angles inside a triangle always add up to 1800 3 identical copies 1800

Types of Triangles Review 2. 1. 3. Equilateral Triangle Isosceles triangle Scalene triangle 3 equal sides 2 equal sides 3 unequal sides 3 equal angles. 2 equal angles (base) 3 unequal angles 4. 5. Any triangle containing a 90 o angle is a rightangled triangle The angle sum of a triangle = 1800

Calculating unknown Angles Example 1 65 o Calculate angle a. a You know that 1800 is the total sum of the angles inside a triangle. Angle a = 180 – (90 + 65) = 180 – 155 = 25 o Example 2 b Calculate angles a, b and c a c

Calculating unknown Angles Example 3 b Angle a = 65 o (base angles of an isosceles triangle are equal). Calculate angle a. 65 o Angle b = 180 –(65 + 65) a = 180 – 130 = 50 o Angle b = 50 o Example 4 Calculate angles x and y 130 o x y

Calculating unknown Angles 90 o Example 5 Calculate angles a and b. a b Example 6 27 o Calculate angle a 15 o Angle a = 180 – (15 + 27) = 180 – 42 = 138 o a

Find the missing angle

**KEY* Find the missing angle

Find the missing angle

**KEY* Find the missing angle

Solve for the missing Angles Go to this interactive site link below. Go to Triangles. Click on Interactive. Click on the triangles in each picture until you find the “active” triangle to solve. http: //www. learnalberta. ca/content/mejhm/index. html? l=0&ID 1=AB. MA TH. JR. SHAP&ID 2=AB. MATH. JR. SHAP. TRI&lesson=html/video_intera ctives/triangles. Small. html

Complete the Triangle Practice pages on our website. Correct these pages using the answer key provided. Send in your corrected practice pages on Seesaw.