A square is inscribed in a right triangle, as shown below. The legs of the triangle are 1 and 3. Find the area of the square.
Side of the square = [product of leg lengths ] / [ sum of leg lengths ] = [ 1 * 3 ] / [ 1 + 3] = 3 / 4
Area of square = [3/4]^2 = 9 / 16