The sum of the legs of a right-angled triangle is 79 cm. If one of the legs is increased by 23 cm and the other
The sum of the legs of a right-angled triangle is 79 cm. If one of the legs is increased by 23 cm and the other reduced by 11 cm, then the new right-angled triangle will have a hypotenuse of the same length as this one. find the lengths of the legs of this triangle.
1. For a right-angled triangle, the sum of the legs is known: Sk;
Sk = X + Y = 79 cm;
Y = 79 – X;
2. The hypotenuse of the triangle is: Z = X² + Y²;
3. We increase the first leg:
X1 = X + 23;
4. Reduce the second leg:
Y1 = Y – 11;
5. Hypotenuse of the new triangle: Z1 = X1² + Y1²;
6. According to the problem statement: Z1 = Z;
X1² + Y1² = X² + Y²;
(X + 23) + (Y – 11) = X² + Y²;
7. Substitute:
(X + 23) ² + (79 – X – 11) ² = X² + (79 – X) ²;
X² + 46 * X + 529 + 4624 – 136 * X + X² = X² + 6241 – 158 * X + X²;
68 * X = 1088;
X = 1088/68 = 16 cm;
Y = 79 – 16 = 63 cm.
Answer: the length of the first leg is 16 cm, the second is 63 cm.