Answer:

Step-by-step explanation:
The diagonal forms two 45-45-90 triangles, with the diagonal being the hypotenuse of both. The Pythagorean Theorem states that
, where
is the hypotenuse of the triangle, and
and
are the two legs of the triangle.
From the Isosceles Base Theorem, the two legs of a 45-45-90 triangle are always equal. Since we're given a diagonal of
, we have:

Surface area will consist of:
2 triangles, 3 rectangles:
Solving for triangles:
A=1/2bh
A=1/2(120)
A=60
60*2 gives us the surface area of both triangular sides.
Solve for rectangles:
(17*20)+(8*20)+(15*20)
(340)+(160)+(300)
(800)
800+120=920
The surface area of the prism is 920 square feet
Answer:
c = 5
Step-by-step explanation:
a^2 + b^2 = c^2
3^2 + 4^2 = c^2
9 + 16 = 25
c^2 = 25
sqrt of 25 = 5
c= 5