Question

A ladder makes an angle of 30° with the floor while leaning against the wall of height 20 m. Keeping foot of the ladder fixed, it is made to lean against another opposite wall and now it makes an angle of 45° with the floor. Find the height of the opposite wa

Answer 1

Answer:

Step-by-step explanation:

Here is the step wise explanation . Comments me if u haven't understood and if understood then follow me

Answer 2

Answer:

Height of opposite wall is 20√2 m or 28.28 m.

Step by step solution:

Find the height of the opposite wall,first find the length of ladder,because ladder is same in both the cases

For case 1: BC is wall

height of wall = 20 m

Length of Ladder AB

$sin \: 30° = \frac{BC}{AB} \\ \frac{1}{2} = \frac{20}{AB} \\ \\ AB= 40 \: m$

Now without sliding the foot of Ladder,it is made to lean against another opposite wall and now it makes an angle of 45° with the floor.

See attached figure 2,

length of Ladder DF= 40 m

angle so formed with floor = 45°

$sin \: 45 = \frac{FE}{DF} \\ \\ \frac{1}{ \sqrt{2} } = \frac{FE}{40} \\ \\ FE= \frac{40}{ \sqrt{2} } \\ \\ = 20 \sqrt{2} m \\ \\FE=28.28 m$

Hope it helps you.