Step 1: Find the area of the square with side lengths of 20: 400
Step 2: Find the area of the square with side lengths of 15: 225
Step 3: Find the sum of the areas of the two squares: 625
Step 4: State the length of the hypotenuse: 625

Which best describes Imara’s error?
She should have found the area of the square with side lengths of 15 first.
She did not correctly calculate the area of the square with side lengths of 15.
She should have found the sum of 15 and 20 and then squared the sum.
She did not find the side lengths of the square with an area of 625.