Question

a painter need to cover a triangular region 63 meters by 68 meters by 75 meters a can of paint covers 70 square meters how many cans will be needed

Answer 1

Here, you can use Heron's formula to find the area since you don't have a value for height.
Heron's Formula: \[A=\sqrt{s(s-a)(s-b)(s-c)}\]
The "s" is the semiperimeter, which is half of the perimeter, in this case 103.
Plugging this into the equation:
\[A=\sqrt{103(103-63)(103-68)(103-75)}\]
Simplify to
\[A=\sqrt{103(40)(35)(28)}\]
This becomes:
\[A=\sqrt{4037600}\]
This is approximately 2009.
Since we know the area is 2009, dividing by 70 will gives us the required number of cans.
2009/70=28.705
Since in this situation we need a whole number of paint cans, round up to get 29.