Answer:
A
Step-by-step explanation:
see the attached figure to better understand the problem
we know that
The equilateral triangle has three equal sides
so
in the equilateral triangle ABC

the height of the triangle is the segment BD
in the right triangle BCD
Applying the Pythagorean Theorem

solve for BD

substitute the values



therefore
<u>the answer is</u>
the height of the triangle is 
Answer:
x=13
Step-by-step explanation:
if you will substitute the value of f(x) with 5, you will get the following equation:
5=2x-21
2x=26/÷2
x=13
(I didn't know what you ment when you wrote x2, is it x square or 2X)
I really hope it was the second one, cause that's how I solved it.
it would be 94 hope this helps