Since the side lengths of the square is seven inches, the legs of the triangle to find the diagonal will be 7 inches as well. Since we have the two legs to find the hypotenuse which is equal to the square’s diagonal, we can find the diagonal by squaring the two legs and adding them together, then finding the square root of the answer.
7•7=49
7•7=49
49+49= 98
Now let’s find the square root of 98. I usually go to the hundredths place since I know 98 doesn’t have a perfect square.
9.9•9.9= 98.01 (the hundredths place rounded to that)
So the length of the square’s diagonal is about 9.9 inches.