Question

Find the angle made by a ladder of length 5m with the ground , if one of its end 4m away from the wall and other end is on the wall.

Answer 1

REF.Image

The ladder leaning on the wall forms a right angled triangle.

Let the right angled triangle formed be of side a,b and c.

Now :

a= the height = the height of the wall.

b= the base = The distance between the ladder and the wall.

c= The hypotenuse = the length of the ladder

In our case :

C= 5 cm

b= 4 m

Let the angle that the ladder makes with the ground be O.

Since b is adjacent and c is the hypotenuse we will use cosine

$cosO=\frac{adj}{hyp}$

$cosO=\frac{4}{5}$

$O=co{s}^{-1}\left(\frac{4}{5}\right)$

$O={40.97}^{\circ }$

$\therefore$ The angle that the ladder makes with the ground is ${40.97}^{\circ }$