One leg of a right-angled triangle is 5 cm smaller than the other. Find the length of each leg if the area
One leg of a right-angled triangle is 5 cm smaller than the other. Find the length of each leg if the area of this triangle is 42 cm²
Let’s denote by x the length of the larger leg of this right-angled triangle.
According to the condition of the problem, one leg of this right-angled triangle is 5 cm less than the other, therefore, the length of the smaller leg of this right-angled triangle is x – 5 cm.
It is also known that the area of this triangle is 42 cm ^ 2, therefore, we can draw up the following equation:
x * (x – 5) / 2 = 42.
We solve the resulting equation:
x * (x – 5) = 84;
x ^ 2 – 5x – 84 = 0;
x = (5 ± √ (25 + 336)) / 2 = (5 ± 19) / 2;
x = (5 + 19) / 2 = 24/2 = 12 cm.
We find the second leg:
x – 5 = 12 – 5 = 7 cm.
Answer: the legs of this right-angled triangle are 7 cm and 12 cm.