To determine the area of the third square in order for the triangle to have a right angle, we can utilize the Pythagorean theorem. The theorem states that in a right triangle, the square of the length of the hypotenuse (the longest side) is equal to the sum of the squares of the lengths of the other two sides.
Let:
- \( A \) be the area of the first square, which has area \( 16 \) units². Thus, the side length \( a \) of Square A is \( \sqrt{16} = 4 \) units.
- \( B \) be the area of the second square, which has area \( 80 \) units². Thus, the side length \( b \) of Square B is \( \sqrt{80} = 4\sqrt{5} \) units.
Let \( C \) be the area of the third square, and the side length \( c = \sqrt{C} \).
According to the Pythagorean theorem: \[ c^2 = a^2 + b^2 \] Substituting the values: \[ c^2 = 16 + 80 = 96 \] Thus, the area of square C must be: \[ C = c^2 = 96 \text{ units}^2 \]
Therefore, the area of the third square must be 96 units² for the triangle to have a right angle.