Question

A ladder 15 m long just reaches the top of a vertical wall. If the ladder makes an angle of 60° with the wall, then the height of the wall is
(a)15√3m
(b)$\frac{ 15\sqrt{3}} {2}m$
(c)${\frac{15}{2}}m$
(d)15 m

Answer 1

Answer:

The height of the wall is 15/2 m  .

Among the given options option (c) 15/2 m  is correct.

Step-by-step explanation:

GIVEN :

Length of the ladder , AC = 15 m  

A ladder makes an angle with the wall , ∠BAC = 60°

Let AB be the height of the wall.

In right angle triangle, ∆ABC ,

cos 60°  = B/H =  AB/AC  

½ = AB/15

AB  = 15/2 m

Hence , the height of the wall is 15/2 m  

HOPE THIS ANSWER WILL HELP YOU…

Answer 2

SOLUTION

Let AB be the ladder & AC be the wall.

Given,

AB= 15cm & ∠BAC= 60°

Now, In right ∆ACB,

$cos60 \degree = \frac{</strong><strong>AC</strong><strong>}{</strong><strong>AB</strong><strong>} \\ \\ = > \frac{1}{2} = \frac{</strong><strong>AC</strong><strong>}{15m} \\ \\ = > </strong><strong>AC</strong><strong> = \frac{15}{2} m = 7.5m$

Hence, the height of the wall is 7.5m

hope it helps ☺️