Hey there.
The second option would be the correct one.
You can use the Pythagorean theorem to solve this.
a^2+b^2=c^2
we're given one leg and the hypotenuse so just plug that in.
5.7^2+b^2=18^2
You can subtract 5.7^2 from both sides to get"
b^2=18^2-5.7^2
After you subtract, you just have to square root the answer in order to solve for b aka the height.
