Answer:
15√3 meters ≈ 26 meters
Step-by-step explanation:
The three boys are sitting at equal distances on the circle, so they form an equilateral triangle.
Draw one line cutting the triangle in half, and another line from one corner to the center of the circle. These two lines form a large 30-60-90 triangle on one side, and a smaller 30-60-90 triangle on the other side.
The hypotenuse of the smaller triangle is the radius of the circle, so the short leg is equal to 7.5 meters. That means the height of the equilateral triangle is 15 meters + 7.5 meters = 22.5 meters.
To find the side length of the equilateral triangle, we can either find the hypotenuse of the larger 30-60-90 triangle, or double the long leg of the smaller 30-60-90 triangle. Either way, it's 15√3 meters.