Question 90

A 10 metre long ladder is placed against a wall. It is inclined at an angle of 30° to the ground. The distance (in m) of the foot of the ladder from the wall is (Given √3 = 1.732)

Solution

AC = ladder = 10 metre

BC = ?

$$\angle$$ACB = 30°

From $$\triangle$$ABC

$$cos 30^{\circ} = \frac{BC}{AC}$$

=> $$\frac{\sqrt{3}}{2} = \frac{BC}{10}$$

=> $$BC = \frac{10\sqrt{3}}{2} = 5\sqrt{3}$$

=> BC = 5*1.732 = 8.66 metre

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