The perimeter is just adding all the sides together.
a.) 180 = 40 + 40 + x + x
180 = 80 + 2x Subtract 80 on both sides
100 = 2x Take 1/2 of 100 to get x
x= 50cm
b.) 1000 = 150 + 150 + x + x
1000 = 300 + 2x Subtract 300 on both sides
700 = 2x Take 1/2 of 700 to get x
x = 350
To find how much cinnamon per pound you first divide the $2.40 by the 3 oz to find how much per ounce...so $2.40/3 = 80 cents. Then u multiply that by the 16 oz to get the amount for 1 pound...so .80x16= $12.80 per pound.
Hope it helps!
Sheesh .........................................
