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?

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

1/2•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. 144•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:

step-by-step explanation:

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