Question

The hypotenuse of a right angled triangle is 20 metres if the different between the length of the other side be 4 metre find other side

Answer 1

Let x be one of the sides then the other side is x - 4

By Pythagoras theorem :

x² +(x - 4)² = 20²

x ² + x² - 8x + 16 = 400

2x² - 8x + 16 = 400

2x² - 8x - 384 = 0

x² - 4x - 192 = 0

x² + 12x - 16x - 192 = 0

x (x + 12) - 16(x + 12)

( x + 12)(x - 16) = 0

x = - 12 or 16m

We take 16 since it is positive given that length is positive.

The other length is 16 - 4= 12m