Find the area of a right-angled triangle, the hypotenuse is 16 cm, and the sum of the legs is 24 cm.
Let us denote the lengths of the legs of this right-angled triangle through a and b.
According to the condition of the problem, the sum of the legs of this right-angled triangle is 24 cm, therefore, the following relation holds:
a + b = 24.
Also in the condition of the problem it is said that the hypotenuse of this right-angled triangle is 16 cm? therefore, the following relation holds:
a ^ 2 + b ^ 2 = 16 ^ 2.
We square both sides of the first ratio and transform as follows:
(a + b) ^ 2 = 24 ^ 2;
a ^ 2 + 2ab + b ^ 2 = 576;
2ab = 576 – (a ^ 2 + b ^ 2);
2ab / 4 = (576 – (a ^ 2 + b ^ 2)) / 4;
ab / 2 = 144 – (a ^ 2 + b ^ 2) / 4.
Since a ^ 2 + b ^ 2 = 16 ^ 2 = 256, and the area S of this triangle is ab / 2, we get:
S = 144 – 256/4 = 144 – 64 = 80 cm ^ 2.
Answer: 80 cm ^ 2.