3. Katie wants to calculate the perimeter of a fountain as shown in the picture below. She does this by counting the number of square tiles around the edge of the fountain. Each tile is a 1-ft by 1-ft square, so she says the perimeter is 16 ft. Fountain Is Katie's method a valid way to find the perimeter of the pool? If her method is valid, explain why. If her method is not valid, explain why and calculate the perimeter of the pool using a valid method.