Answer:
You have to add the lengths of all the sides together.
STEP 1
calculate total ounces
= 16 oz/lb * 3 lbs
= 48 ounces
STEP 2
calculate number of bolts; divide total weight (48 ounces) by ounces per bolt
x= number of bolts purchased
x= 48 ounces ÷ 1/15 oz per bolt
x= 48 ÷ 1/15
to divide by fraction; multiply by reciprocal of 1/15
x= 48 * 15/1
x= 720 bolts
ANSWER: He purchased 720 bolts
Hope this helps! :)
If we can assume those are semi circles, the answer is 5+7.5pi. However, you would need more information if they are not perfect semicircles.