A pyramid has a base in the shape of a rhombus and a peak directly above the base's center. The pyramid's height is 1 , its base's sides have lengths of 7 , and its base has a corner with an angle of ( pi)/4 . What is the pyramid's surface area?

1 Answer
Apr 29, 2018

color(indigo)(T S A = A_T = 34.65 + 50.96 = 85.61 " sq units"

Explanation:

https://socratic.org/questions/a-pyramid-has-a-base-in-the-shape-of-a-rhombus-and-a-peak-directly-above-the-bas-34https://socratic.org/questions/a-pyramid-has-a-base-in-the-shape-of-a-rhombus-and-a-peak-directly-above-the-bas-34

l = 7, h = 1, theta = pi/4, " To find surface area of pyramid"

"Area of base " A_b = l^2 sin theta = 7^2 * sin (pi/4) = 34.65

"Slant height of pyramid " s = sqrt(h^2 + (l/2)^2) = sqrt(1^2 + (7/2)^2) = 3.64

"Lateral Surface Area of Pyramid " A_l = 4 * (1/2) * l * s

L S A = A_s = 4 * (1/2) * 7 * 3.64 = 50.96

"Total Surface Area " = T S A = A_T = A_b + A_s

color(indigo)(T S A = A_T = 34.65 + 50.96 = 85.61 " sq units"