Answer:
277 cm^2
Explanation:
Two of the triangular faces will have areas of ...
A = 1/2bh = (1/2)(8 cm)(11 cm) = 44 cm^2
and the other two will have areas of ...
A = 1/2bh = (1/2)(9 cm)(13 cm) = 58.5 cm^2
The base will have an area of ...
A = LW = (9 cm)(8 cm) = 72 cm^2
So, the total area will be ...
2(44 cm^2) +2(58.5 cm^2) +72 cm^2 = 277 cm^2
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Comment on the problem
You could not actually build this pyramid. The height of the peak above the 8-cm edges must be ...
√(11^2 -(4.5)^2) = 10.04 cm
The height of the peak above the 9-cm edges must be ...
√(13^2 -4^2) = 12.37 cm.
The peak cannot be in two places at once. This geometry is impossible.