EXERCISE  6.2

QUESTION 1

Find the value of the unknown exterior angle x in the following diagrams:

(i) x = 50° + 70° (Exterior angle theorem)

x = 120°

(ii) x = 65° + 45° (Exterior angle theorem)

x = 110°

(iii) x = 40° + 30° (Exterior angle theorem)

= 70°

(iv) x = 60° + 60° (Exterior angle theorem)

= 120°

(v) x = 50° + 50° (Exterior angle theorem)

= 100°

(vi) x = 30° + 60° (Exterior angle theorem)
= 90°

 

QUESTION 2

Find the value of the unknown interior angle x in the following f‌igures:

(i) x+ 50° = 115° (Exterior angle theorem)

x = 115°— 50° = 65°

(ii) 70° + x = 100° (Exterior angle theorem)

x = 100° – 70° = 30°

(iii) x+ 90° = 125° (Exterior angle theorem)

x = 125° – 90° = 35°

(iv) x+ 60° =120° (Exterior angle theorem)

x = 120° – 60° = 60°

(v) x+ 30° = 80° {Exterior angle theorem)

x = 80° — 30° = 50°

(vi) x + 35° = 75° (Exterior angle theorem)

x = 75° — 35° = 40°