Question

how far from the base of the building a ladder of length 2.9 metre should be placed so that it exactly reaches at the height 2 metre of the building​

Answer 1

Step-by-step explanation:

The ladder forms a right angled triangle with the wall and the base with length of the ladder being the length of hypotenuse of this triangle.

Hypotenuse =25 m

Base =7 m

Height =25

2

−7

2

=24 m

Now the ladder slides. In the new position, the hypotenuse of the new right angled triangle will be the same.

The top slides down by a distance 4m. Hence, the height is 24−4=20 m. Let the base slide by a distance x. Therefore, hypotenuse =25 m

Base =(7+x) m

Height =20 m

By Pythagoras Theorem, we get

25

2

−20

2

=(7+x)

2

∴(7+x)=15

Hence, x=8