Question

Kiana wants to cover a triangular area of her background with red, concrete patio stones. Each stone costs $0.42 and covers 29.26 square inches. if the triangular area has a height of 8 feet and a width of 6 feet, what is the minimum number of stones that Kiana should buy to cover the triangular area in her backyard? Show your work.

Answer 1

1. The problem says that the stone covers 29.26 square inches. So, the first thing you must do, is to convert 29.26 square inches (in²) to square feet (ft²):

 1 in²=0.00694 ft², then:

 29.26x0.00694= 0.20 ft²

 2. The triangular area has the following surface: 

 A=bxh/2
 A=(6 ft)(8 ft)/2
 A=24.0 ft²

 3.  Finally, the number of stones (N) that cover the triangular area is:

 N= 24.0 ft²/0.20 ft²
 N=120 stones

 Answer: Kiana should buy 120 stones to cover the triangular area in her backyard.