Answer:
a = 36°
b = 144°
Step-by-step explanation:
Method 1
Number of sides = n = 10
Sum of interior angles = (n - 2) × 180°
= (10 - 2) × 180°
= 8 × 180°
= 1440°
Interior angle = b = sum of interior angles ÷ number of sides
b = 1440 ÷ 10
b = 144°
a + b = 180° (Sum of angles in the straight line)
a + 144° = 180°
a + 144° - 144° = 180° - 144°
a = 36°
Method 2
Number of sides = 10
Exterior angle = a = 360° ÷ Number of sides
a = 360° ÷ 10
a = 36°
a + b = 180° (Sum of angles in the straight line)
36° + b = 180°
36° + b - 36° = 180° - 36°
b = 144°
