Answer:
9 sides
Step-by-step explanation:
Two methods and the same answer = 9 sides
Method 1: Since the interior angle 140 degrees, the supplement of this is the exterior angle and equal to 40 degrees. Hence the number of sides is 360/40 = 9 sides.
Method 2: Since the exterior angle 140 degrees, The sum of the interior angles = (2n - 4)* right angles. So 140n =(2n - 4)* right angles, or
140n =(2n - 4)*90, or
140n = 180n - 360, or
40n = 360, or
n = 9 sides.
Hence the number of sides is 9 sides.
