Answer:
x = 180
Step-by-step explanation:
First, you need to know
1. Double-angle formula:
cos(2x) =
2. Pythagorean identity:
Back to your problem, replacing the variable by the above:
By Double-angle formula
By Pythagorean identity
Given
, we know -1 < sinx < 1, for every x ∈ R
I assume you meant "surface area" :)
Looking at the net, it looks like if you folded it back together it would form to become a triangular prism.
To calculate the surface area of a triangular prism, you would use the formula: A = bh + 2ls + lb, where b is the base of the triangular faces, h is the height of the prism, l is the length of the prism, and s is the side length of the prism.
I attached a picture to help you see what these labels are.
Looking at the diagram you've provided, we can assume that b = 7 cm, h = 4 cm, l = 8 cm, and s = 5 cm. Substitute these into the formula.
A = bh + 2ls + lb ==> A = (7)(4) + 2(8)(5) + (8)(7)
Multiply from left to right.
28 + 80 + 56
Add.
164
The surface area of this triangular prism is A) 164 cm^2.
