Question

the base of a right prism is an equilateral triangle whose edges is 10cm each and its lateral edge is 80 cm. Determine the total surface area of the prism in cm2

Answer 1

Total surface area of a prism:

$S=2B+Ph$

Where

B = Base area

P = perimeter of the base

h = height of the prism

Since we have equilateral triangle, its area is:

$B=\frac {\sqrt3} 4 a^2$

and perimeter is $P=10*3=30 cm$

where a is the edge of triangle.

So, the total surface area of a prism:

$S=\frac {2\sqrt3} 4 *10^2+30*80\approx2486,6 cm^2$