A boy sighted the school flag pole at a point which is 20m from the foot of the pole, and due east of the pole. if the angle of elevation of the top of the flag pole from the boy is 21degree find the height of the flag pole.
Let's call the height of the flagpole "h".
We can use trigonometry to solve the problem. We know that the boy is standing 20m away from the foot of the pole, and that the angle of elevation from the boy to the top of the pole is 21 degrees. We can draw a right triangle, where the hypotenuse is the line from the boy to the top of the pole, the adjacent side is the distance from the foot of the pole to the boy (20m), and the opposite side is the height of the pole (h).
We can use the tangent function to solve for h:
tan(21) = h/20
To solve for h, we can multiply both sides by 20:
20 tan(21) = h
Using a calculator, we can find that:
h ≈ 7.28
Therefore, the height of the flagpole is approximately 7.28 meters.