A 9m long ladder rests at 9m below a vertical wall. If the angle of elevation of the top of the wall from the foot of the ladder

Question

4 years ago

15

is 60°. Find the height of the wall.
Plz do it fast
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1 answer:

Arte-miy333 [17] · Answer 1 · 2022-01-17T04:10:59+03:00

Height of the wall is 27 m.

<u>Explanation:</u>

Let the height of the wall = h

Length of the ladder = 9 m

Angle of elevation = 60°

Ladder rests at 9 m below a vertical wall.

So, length of the wall upto which the ladder rests = h - 9

We know,

Cos Ф = base/ hypotenuse

cos 60° = length of the ladder / height of wall upto which the ladder rests

$\frac{1}{2} = \frac{9}{h - 9}$

So,

h - 9 = 18

h = 27

Therefore, height of the wall is 27 m