A painter needs to cover a triangular region 65 meters by 69

A painter needs to cover a triangular region 65 meters by 69 meters by 71 meters. A can of paint covers 70 square meters. How many cans will be needed?

Solution

let sides are a=65, b=69,c=71

s=(a+b+c)_/2

s=(65+69+71)_/2

s=102.5

area of triangle =[s(s-a)(s-b)(s-c)]

area of triangle =[102.5(102.5-65)(102.5-69)(102.5-71)]

area of triangle =2013.98square meters

a can of paint covers 70 square meters

number of cans needed =2013.98_/70

number of cans needed =28.77

29 cans will be needed