(12 - 2) * 180 = 1,800/12 = 150
(8 - 2) * 180 = 1,080/8 = 135
B. 8 sides
TO find perimeter you add all sides. But to find the totaly of each side, you will divide. So a triangle has 3 sides, so you divide 45 by 3 to get the sides length of:
15 cm each
~hope this helped :)
Answer:
200
Step-by-step explanation:
Use the ratio: 20/100 = 40/X
Simplify the ratio: 1/5 = 40/X
Cross Multiply: 1X = 200
Divide both sides by 1: 1X/1 = 200/1
Simplify: X = 200
His error is he forgot the 2 in 2 3/4