Answer
[tex]\sqrt{33}[/tex]
Explanation
You can find the length of AC using the Pythagorean Theorem.
[tex]l^{2}+l^{2}=h^{2}[/tex]
The legs, are AB and AC. They are the shortest sides.
The hypotenuse is BC. It is the longest side.
You know one of the legs are 4.
You know the hypotenuse is 7.
So plug those into the equation.
[tex]4^{2} + l^{2} = 7^{2}[/tex]
Well, 4 squared is 16.
7 squared is 49.
[tex]16 + l^{2} = 49[/tex]
Well you can rearrange the equation to find the remaining leg.
[tex]49-16=l^{2}[/tex]
So now you can solve for it.
[tex]49-16=33[/tex]
[tex]33=l^{2}[/tex]
Since the leg is squared, you can undo it by using the square root.
Therefore the length of AC is the third choice.
