Explanation
A tower of height $$'h'$$ standing vertically at the center of a square f side length $$'a'$$ subtends the same angle $$'\theta '$$ at all the corner points of the square. Then
Let $$BC$$ is a tree of height $$12 m$$ and shadow of tree $$AB = x$$ m and angle of elevation of sun $$= 45^{0}$$
i.e., $$\angle CAB = 45^{0}$$
From right angled $$\Delta ABC$$,
$$\tan 45^{0} =\dfrac{BC}{AB}$$
$$1 =\dfrac{12}{x}$$
$$x = 12 m$$
Hence, length of shadow of tree = $$12 m$$
So, correct choice is (D).
Let $$A$$ is a kite which is $$30$$ meter high from the ground which is flying with string of $$60 m$$ long.
Let $$\angle ACB = \theta$$
From right angled
$$\sin \theta =\dfrac{AB}{AC}$$
$$\sin \theta =\dfrac{30}{60}$$
$$\sin \theta =\dfrac{1}{2}$$
$$sin \theta = \sin 30^{0}$$
$$\theta = 30^{0}$$
So, correct choice is (B)
Let $$BC$$ be the height of the hill and $$AB = x$$ be the distance of point from the foot.
Also, the length between $$A$$ to $$C$$ i.e., $$AC = 300 m$$ and $$\angle BAC = 60^{0}$$
$$\cos 60^{0} =\dfrac{AB}{AC}$$
$$\dfrac{1}{2} =\dfrac{x}{300}$$
$$x =\dfrac{300}{2}$$
$$\therefore x = 150 m$$
Hence, distance of point from base is $$150 m$$.
So, the correct choice is (B).
Please disable the adBlock and continue. Thank you.