Angles Revising Basic Angles Naming Angles Calculating Missing

Angles Revising Basic Angles Naming Angles Calculating Missing angles Angles in a Triangle Corresponding Angles Alternate Angles 10 -Jan-22 1

Type of Angles Vertical Acute less than 90 o Straight Line Angle exactly 180 o 10 -Jan-22 Horizontal Right - Angle exactly 90 o Obtuse Between 90 o – 180 o reflex over 180 o less than 360 o 2

The angle highlighted is: A Acute B Right Angled C Obtuse D Straight E Reflex 10 -Jan-22 3

Naming Angles A B X C Z Y Type of angle is acute Type of angle is obtuse Name of angle is ∠ ABC Or ∠ CBA Name of angle is ∠ ZYX Or ∠ XYZ MIDDLE LETTER IS ALWAYS THE VERTEX ALWAYS 3 CAPITAL LETTERS 10 -Jan-22 4

Examples Name & state the type of angle for the shape below: - P Q R S 10 -Jan-22 ∠ PQS is right angled ∠ PRS is right angled ∠ PSR is acute ∠ RPS is acute ∠ PSQ is acute ∠ QPS is acute 5

Q Which Statement is FALSE? R P A ∠ PQR is Obtuse B ∠ QRS is Obtuse C ∠ STR is Right Angled D ∠ RST is Acute E ∠ SRT is Acute S 10 -Jan-22 T 6

Calculate Missing Angles 2. 1. 65 o 115 o 65 o 25 o 4. 3. 34 o 123 o 120 o 95 o 145 o 10 -Jan-22 7

Calculate the missing angle. 76° ? 10 -Jan-22 A 256° B 166° C 104° D 76° E 14° 8

The missing angle is 110° 146° TRUE or FALSE? 104° ? 10 -Jan-22 9

Related Angles 55 o 35 o Two angles making a o right angle add to 90 (Complementary angles) 10 -Jan-22 115 o 65 o Two angles making a o straight line add to 180 (Supplementary angles) 10

Calculate the supplement of 163 °. 10 -Jan-22 A 13° B 17° C 73° D 197° E 343° 11

Calculate the complement of 30 °. 10 -Jan-22 A 150° B 120° C 90° D 60° E 30° 12

Opposite Angles are equal. a=b c=d c° aº d° bº 10 -Jan-22 13

Calculate Missing Angles 1. 145 o 35 o 145 o 2. 35 o 98 o 82 o 98 o 3. 43 o 58 o 10 -Jan-22 79 o 58 o 43 o 14

Calculate angles m & n m 10 -Jan-22 n 67° A m=67° & n= 67° B m=113° & n= 67° C m=67° & n= 113° D m=67° & n= 127° E m=127° & n= 67° 15

To determine the angle sum of any Triangle Cut off corners 10 -Jan-22 16

All angles in a triangle o add up to 180 10 -Jan-22 o 17

Calculating Missing Angles Copy out the following triangles and find the missing angles. x 87 o 61° 38 o 50 o o 32 o x o 52° x o 65° Remember all the angles add up to 180 10 -Jan-22 x o 65° o 18

Calculate the missing angle 76° 37° 10 -Jan-22 ? A 67° B 76 ° C 77 ° D 113 ° E 114 ° F 247 ° 19

Corresponding Angles look for Parallel Lines shapes 10 -Jan-22 20

Corresponding Angles Which angles are equal? 10 -Jan-22 21

Which angles are equal to the shaded angle? 10 -Jan-22 22

The value of x is 131°. x° 131° True or False? 10 -Jan-22 23

Example 123 57 What are the values of the missing angles? 123 10 -Jan-22 24

The angle marked is: - ? 54° 10 -Jan-22 A 180° B 136 C 126° D 124 E 54 ° F 34 ° ° ° 25

Alternate Angles Look for - Z shapes = equal angles 10 -Jan-22 26

Example Find the value of a. 35° a 10 -Jan-22 27

Find the value of d. 123° d 10 -Jan-22 A 180° B 123° C 190° D 57° 28

Example 50 ° Find the value a and b a ° 130 b ° 50 10 -Jan-22 29

Example 135° Find the value of a and b. c ° 45 45 d° 10 -Jan-22 30

q 37° 10 -Jan-22 Find the value of q A 37° B 53° C 143° D 153° E 180 ° F 223 ° 31

Extension 124° 56° 124° Find all the missing angles 124 ° 56° 10 -Jan-22 56 ° 124° 32