Question

John is 12 meters away from a cliff and looks up to the top of the cliff at an angle of 45. His eyes are 2 meters above the ground. How tall is the cliff? ​

Answer 1

14m

Explanation:

Please refer to the attached figure
B is the position where John is standing, His eyes are at point A, 2 meters from the ground

D is the base of the cliff and E is the top of the cliff

∠EAC is the angle at which John looks up to the cliff and is given as 45°

BD is the distance from the cliff given as 12m

So AC is also 12m

∠ACE is 90°

Therefore ∠AEC is 180-(45+90) = 45° since AEC forms a triangle and sum of angles in a triangle = 180°

In the ΔAEC, by the law of sines
12/sin(45) = EC/sin(45) . This means EC = 12 since the denominators cancel out

Since point C is 2 meters above ground(the base of the cliff) add 2 and we get the height of the cliff as 12+2 = 14m