Question

The following picture is a square pyramid where DE=8 cm and m∠ADE=60°.

Answer 1

Answer:

131 cm

Step-by-step explanation:

formula for surface area of pyramid is

S = (1/3)Bh

but the base ia a square, so B = $x^{2}$

S = (1/3)$x^{2} h$

the pic shows h = 8

but we don't know x

do SohCahToa

sin60 = x/8

x = 8sin60

x = 6.92820323 or 7

plug in numbers

S = (1/3)$7^{2}$8

S = 392/3

S = 130.6666667 or 131 cm