The difference between the legs of a right-angled triangle is 23 dm, and its hypotenuse is 37 dm.
The difference between the legs of a right-angled triangle is 23 dm, and its hypotenuse is 37 dm. Find the perimeter of the triangle.
Suppose that one of the legs of a given right-angled triangle is x, then the second leg, according to the condition of the problem, will be x – 23.
Let’s use the Pythagorean theorem and compose the following equation:
x² + (x – 23) ² = 37²,
x² + x² – 46 * x + 529 = 1369,
2 * x² – 46 * x – 840 = 0,
x² – 23 * x – 420 = 0.
The discriminant of this equation is:
(-23) ² – 4 * 1 * (-420) = 2209.
Since x can only be a positive number, the problem has a unique solution:
x = (23 + 47) / 2 = 35 (dm) – the length of the larger leg.
32 – 23 = 12 (dm) – the length of the smaller leg.
Therefore, the perimeter of this triangle is:
P = 37 + 35 + 12 = 84 (dm).