The triangle shown is a right triangle. Create the equation to be used to find the missing lengths. (Enter the smaller leg of the triangle first.) Do not solve the equation.

We need to use the pythagorean theorem.
4²+7²=c²
This'll be the equation but, you can simplify is a bit more.
√(4²+7²)=c
Simplifying it allows anyone to get the result rather than doing extra steps.
√(4²+7²)=c is the equation.