By applying the Pythagorean theorem to the rectangular room with a given diagonal of 13 ft and one wall 7 ft longer than the other, we solve for x to find that the dimensions of the room are 5 ft by 12 ft.
To determine the dimensions of the room when the diagonal is 13 ft long and one wall is 7 ft longer than the adjacent wall, we can use the Pythagorean theorem. Let's denote the length of the shorter wall as x ft. Therefore, the length of the longer wall will be x + 7 ft. Since the diagonal forms a right triangle with the walls of the room, by the Pythagorean theorem:
c² = a² + b²
Where c is the diagonal, and a and b are the length and width of the room, respectively. Plugging in the values we have:
13² = x² + (x + 7)²
Solving for x:
169 = x² + x² + 14x + 49
2x² + 14x - 120 = 0
Dividing the entire equation by 2:
x² + 7x - 60 = 0
Factorizing the quadratic equation:
(x + 12)(x - 5) = 0
Therefore, x = -12 or x = 5. Since a dimension cannot be negative, x must be 5 ft. Hence, the shorter wall is 5 ft, and the longer wall is 5 + 7 = 12 ft. The dimensions of the room are therefore 5 ft by 12 ft.