Please help with math problem?

Question

A water trough is the shape of a prism. The ends are equilateral triangles. Each side of the triangle is 1 foot in length. The trough is 9 feet long. How many litres of water will the trough hold? 10^3 cm = 1 Litre

Answer 1

First convert your lengths into cm

1ft = 12*2.54 = 30.48cm.

9ft = 9*12*2.54 = 274.32cm

The area of the end of the prism can be found using the equation

Area = (1/2)absinC

Area = (1/2)*30.48*30.48*sin60 (since it's equilateral, all its angles are 60 degrees)

Area = 402.28cm^3

Divide this by 10 to get the number of litres

It can hold 40.22 litres.