Answer:
12
Step-by-step explanation:
12 divided by 3 is 4 and 4 times 3 is 12
Hey there! :) In order to find the perimeter, you must add all 4 sides. You first do 16.8 + 16.8 + 9.6 + 9.6 which is 52.8.
Hope it helps!
Answer:
interior angle of a heptagon = 900 degrees
900 = 4x + (3x + 60)
840 = 7x
840/7 = 120
X = 120
120 X 4 = 480
120 X 3 = 360
480 + 360 + 60 = 900
4 angles = 120 degrees each
3 angles = 140 degrees each