Question

The triangle ABC above shows the angle of elevation of the top, B, of a tower, BC, from A, to be 30. AB=40 m. The length of BC is

Answer 1

Answer:

sorryI don't know the the full answer II of this question.

Answer 2

Given:

In ΔABC,

BC is the height of the tower with B representing the top of it

The angle of elevation from point A is 30°

The length of AB = 40 m

To find:

The length of BC

Solution:

We will use the following trigonometric function of a triangle to solve the given problem:

$\boxed{\bold{sin \;\theta = \frac{Opposite \:side}{Hypotenuse} }}}$

Here in Δ ABC, we have,

θ = 30°

Opposite side / Perpendicular = BC

Hypotenuse = AB = 40 m

∴ $sin \;30 = \frac{BC}{AB} }}}$

substituting the sin 30° = $\frac{1}{2}$ and AB = 40 m

⇒ $\frac{1}{2} = \frac{BC}{40} }}}$

⇒ $BC = \frac{40}{2}$

⇒ $\bold{BC = 20 \: m}$

Thus, the length of BC is 20 m.

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