Answer:
11.) 135° 12.) 45°
Explanation:
11.) When finding one interior angle, you will have to first find the sum of the interior angle using the formula:
Sum of interior angle = ( n - 2 ) 180° where "n" is the number of sides of that shape. So the working will be:
( 8 - 2 ) 180°
= 6 x 180°
Sum of interior angle = 1080°
To find the angle of one interior angle, divide it by the number of sides of that shape.
1080° ÷ 8 = 135°
∴ The measure of one interior angle is 135°
12.) To find the exterior angle, use the formula:
Exterior angle = 360° ÷ n where "n" is the number of sides of that shape. So the working will be:
360° ÷ 8 = 45°
∴ The measure of one exterior angle is 45°
Extra: You can check if the answer is correct by multiplying the answer you got for the exterior angle with the number of sides and that should give you 360°.