Question

The area of the base of a prism is 50 mm2. The perimeter of the base is 30 mm. The height of the prism is 7 mm.

What is the surface area of the prism?


mm2

Answer 1

let the base have dimensions a x b. We are told that the base has an area of 50mm2, so ab=50mm2. Also, the perimeter of the base is 30mm, so 2(a+b)=30mm --> a+b=15mm.
So, we need to guess a and b such that if you multiply them you get 50 and if add them you get 15... easy: 5 and 10, that is the dimensions of the base. We are given that the height of the prism is 7mm. The rest you can do. Hope that helps.