https://socratic.org/questions/a-pyramid-has-a-parallelogram-shaped-base-and-a-peak-directly-above-its-center-i-95
l = 8, b = 2, theta = (5pi)/12, h = 9l=8,b=2,θ=5π12,h=9
"To find the Total Surface Area T S A"To find the Total Surface Area T S A
"Area of parallelogram base " A_B = l b sin thetaArea of parallelogram base AB=lbsinθ
A_B = 8 * 2 * sin ((5pi)/12) = 15.45AB=8⋅2⋅sin(5π12)=15.45
S_1 = sqrt(h^2 + (b/2)^2) = sqrt(9^2 + 1^2) = 9.06S1=√h2+(b2)2=√92+12=9.06
S_2 = sqrt(h^2 + (l/2)^2) = sqrt(9^2 + 4^2) = 10.82S2=√h2+(l2)2=√92+42=10.82
"Lateral Surface Area " A_L = 2 * ((1/2) l * S_1 + (1/2) b * S_2Lateral Surface Area AL=2⋅((12)l⋅S1+(12)b⋅S2
A_L = (cancel2 * cancel(1/2)) * (l * S_1 + b * S_2) = (8 * 9.06 + 2 * 10.82)
A_L = 94.12
"Total Surface Area " A_T = A_B + A_L = 15.45 + 94.12 = 109.57