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bekah2297
A prism has a right triangle as its base with a hypotenuse that measures 15 meters and legs that measure 9 meters and 12 meters. What is the surface area of this prism if the height of the prism is 11 meters?
Basically, a triangular prism looks like this |dw:1335213379196:dw| To find the total surface area of this prism, you can decompose it into all of its 5 faces (2 triangles and 3 rectangles). Is this something you think you can do? I'll show you a quicker method one way or the other, but you just need to understand this part first
So, I'll assume that you got it at this point. Now, for the quick way : first, calculate the area of the triangles (the bases of prism) : h*b/2 = 12*9/2 = 54 for one triangle, and since you have 2, 54*2 = 108 for both. Let's put that temporarely in the back of our minds whilst we calculate the rest Now that this is done, you're left with the 3 rectangles. They have something special, these 3 rectangles : they all have the same height (11 in this case). So here is the total area for the 3 of them : 9*11 + 12*11 + 15*11 Since 11 is a common factor to the 3 terms, I suggest we factor it from the addition : 11(9 + 12 + 15) = 396 9+12+15, that looks a lot like the perimeter of your triangle, right? So that's how you can calculate the area of any prism : the area of both bases + (perimeter of the base * height of the prism). So in this case : 2*54 + 11*(9+12+15) = 504 m^2