← Back to Test

Problem 20 - Entrance Test

A kite is flying at a height of 60m above the ground. The string attached to the kite is tied to a point on the ground. If the inclination of the string with the ground is 30°, what is the length of the string?

Correct: B

Let 'L' be the length of the string. This is the Hypotenuse of the right-angled triangle formed. The height of the kite is 60m, which is the Opposite side to the angle of inclination of 30°. We use the sine function: sin(angle) = Opposite / Hypotenuse. sin 30° = 60 / L. We know sin 30° = 1/2. So, 1/2 = 60 / L. Cross-multiplying gives L = 2 × 60 = 120 m.