8 ft 10 ft square feet Submit Continue Sorry, incorrect... The correct answer is: Got it Explanation review You answered: Got it Learn with an example question What is the area of this square? 9 mm square millimeters key idea Area of a square: area=side side solution Find the side length of the square. side: 9 mm Use this number in the formula. area = side side = 9 9 = 81 Now find the units. The lengths are measured in millimeters, so the area is measured in square millimeters. The area is 81 square millimeters. Back to practice Questions answered