The following picture is a square pyramid where DE=8 cm and m∠ADE=60°.
Find the surface area of the pyramid in both exact form and approximate form.

The following picture is a square pyramid where DE8 cm and mADE60 Find the surface area of the pyramid in both exact form and approximate form class=

Respuesta :

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 = [tex]x^{2}[/tex]

S = (1/3)[tex]x^{2} h[/tex]

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)[tex]7^{2}[/tex]8

S = 392/3

S = 130.6666667 or 131 cm