A pyramid has a parallelogram shaped base and a peak directly above its center. Its base's sides have lengths of 1 1 and 4 4 and the pyramid's height is 2 2. If one of the base's corners has an angle of (5pi)/65π6, what is the pyramid's surface area?

1 Answer
Dec 25, 2017

T S A = 13.0748

Explanation:

CH = b1 = 1 * sin ((pi)/6) = 0.5CH=b1=1sin(π6)=0.5
Area of parallelogram base = a * b1 = 4*0.5 = color(red)(2)=ab1=40.5=2

EF = h_1 = sqrt(h^2 + (a/2)^2) = sqrt(2^2+ (4/2)^2)= 2.8284EF=h1=h2+(a2)2=22+(42)2=2.8284
Area of Delta AED = BEC = (1/2)*b*h_1 = (1/2)*1* 2.8284= color(red)(1.4142)#

EG = h_2 = sqrt(h^2+(b/2)^2 ) = sqrt(2^2+(1/2)^2 )= 2.0616
Area of Delta = CED = AEC = (1/2)*a*h_2 = (1/2)*4*2.0616 = color(red)( 4.1232)

Lateral surface area = 2* DeltaAED + 2*Delta CED
=( 2 * 1.4142)+ (2* 4.1232) = color(red)(11.0748)

Total surface area =Area of parallelogram base + Lateral surface area = 2 + 11.0748 = 13.0748

Total Surface Area # T S A = **13.0748**#enter image source hereTotal Surface Area T S A = **13.0748**enter image source here