To find the lateral surface area of a pyramid, you can find the area of each triangle, A = 1/2bh or A = 1/2lw, then multiply by the number of triangles, which would be based on the number of sides of the base; or you can take half the perimeter and multiply by the slant height.
The area of the trapezoid is given by the formula A= (a+b)/ 2 * h
in this question a= 8, b= 10, A= 108 inches², and h is what we have to find, substitute what we have got into the formula and you will have:
108= (8+10) /2 *h
108= 9 *h
h= 108/9
h= 12 inches
6+( c-10)
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