A pyramid has a parallelogram shaped base and a peak directly above its center. Its base's sides have lengths of 7 and 3 and the pyramid's height is 6 . If one of the base's corners has an angle of pi/3, what is the pyramid's surface area?

1 Answer
Sep 13, 2016

82.319

Explanation:

enter image source here

Total surface area = base area (a1) + side area 1 (a2) + side area 2 (a3).

1) base area (a1) = parallelogram area = BxxH
=7xx3xxsin60 = 18.186 , (H=3sin60)

enter image source here

2) side area 1 (a2) =(1/2)xxB1xxS1, (B1=7)

S1=sqrt((6^2+1.5^2))=6.185
a2=(1/2)xx7xx6.185xx2=43.295, (2 sides)

3) side area 2 (a3) =(1/2)xxB2xxS2, (B2=3)

S2=sqrt((6^2+3.5^2))=6.946
a3=(1/2)xx3xx6.946xx2=20.838, (2 sides)

Fianlly, total surface area = a1+a2+a3

=18.186+43.295+20.838
=82.319