Question

The sides forming the right angle of a right-angled triangle are 7 cm and 5 cm. Find the length of its hypotenuse.

Answer 1

The given sides are 7 cm and 5 cm.
Consider triangle ABC with sides AB = 7 cm and BC = 5 cm.

m$\angle$ABC = 90°

By Pythagoras theorem,
[l(AC)]² = [l(AB)]² + [l(BC)]²
= (7)² + (5)²
= 49 + 25
= 74
Hence, the square of the length of seg AC is 74
It means that the length of seg AC is equal to the square root of 74
In symbols, $\left[l\left(\mathrm{AC}\right)\right]=\sqrt{74}\mathrm{cm}$.