# Math Help - How do I find sidelength FG of triangle?

1. ## How do I find sidelength FG of triangle?

How do I find FG?
Can anyone help?

2. Indication:

Use cosine theorem (also known as generalization of the Pythagorean theorem).

3. Originally Posted by xerito
How do I find FG?
Can anyone help?
1. Split the triangle into 2 congruent 30-60-right-triangles. That means h = 5.

2. FG = 2x

$x^2+5^2=10^2~\implies~x=5\sqrt{3}$

Therefore $FG = 10\sqrt{3}$