Question

A rectangular pyramid has a base length, l, of 13.8ft, a base width, w, of 16.7ft, and a slant height, l, of 13.9ft. Find the surface area of the pyramid to the nearest square unit.
A. 654 ft2
B. 700 ft2
C. 720 ft2
D. 800 ft2 A rectangular pyramid has a base length, l, of 13.8ft, a base width, w, of 16.7ft, and a slant height, l, of 13.9ft. Find the surface area of the pyramid to the nearest square unit.
A. 654 ft2
B. 700 ft2
C. 720 ft2
D. 800 ft2 @Mathematics

Answer 1

To find the area of the base use Area=length*width, so
13.8x16.7=230.46

To find the area of the sides use Area=2*(1/2)*(1/2)LH and Area=2*(1/2)*(1/2)WH and then multiple that by 2, so

2*(1/2)*(1/2)*13.8*13.9= 95.91*2=191.82
2*(1/2)*(1/2)*16.7*13.9=116.065*2=232.13

Add them all together,
191.82+232.13+230.46=654.41

Your answer is A

Answer 2

area of base = 13.8 * 16.7 = 230.46 sq ft

area of slanted triangles
smallest = (sqrt(13.9^2 - (13.8/2)^2) * 13.8/2 ) * 2 = 191.82
largest = (sqrt(13.9^2 - (16.7/2)^2) * 16.7/2 ) * 2 = 232.13