SOLUTION: The entrance of the Louvre in Paris is square based pyramid with the height of 21.6m. The side length of the square base is 35m. Calculate the total surface area of the four triang

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Question 1205788: The entrance of the Louvre in Paris is square based pyramid with the height of 21.6m. The side length of the square base is 35m. Calculate the total surface area of the four triangular faces to the nearest square metre.
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Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!


given:
height of h=21.6m
the side length of the square base is a=35m
you have triangular face (sides are a, l,l) and height divides it into two right triangles with sides a%2F2, h, and l
find slant height l
l%5E2=%2821.6m%29%5E2%2B%2835m%2F2%29%5E2
l%5E2=772.81m%5E2
l=sqrt%28772.81m%5E2%29
l=27.7995m

perimeter of base P=4%2A35m
lateral area LA=%281%2F2%29P%2Al+where l is slant height

LA=%281%2F2%294%2A35m%2A27.7995m
LA=1945.965m%5E2
LA=1946m%5E2