A playhouse is in the shape of a regular octagonal pyramid with a side length of 3 feet an a slant height of 12 feet. The wood used to build the walls of the playhouse costs $3 per square foot. What is the cost of the wood for the walls of the playhouse?

Respuesta :

Answer: We just did these problems in my math class today! Ok, so you need to find the lateral surface area, or the area of the faces/walls. The formula for triangles is

1/2 β€’ base β€’ height. Sub in the #s, it would be 1/2 β€’ 6 β€’ 12

1/2β€’72

36

So now we know the area of one of the faces is 36inches^2, we can multiply that by 4, which is 144. 144β€’3($)= $432. To sum things up, $432 is the cost to build the walls of the playhouse, and we are not adding in the base, because the base is not a face!

Step-by-step explanation: