The radius of a circle around a regular triangle = 56 Find the height.
We denote by a the length of the side of this regular triangle.
Since each angle of a regular triangle is 60 °, the area of this triangle should be equal to a * a * sin (60 °) / 2 = a ^ 2 * (√3 / 2) / 2 = a ^ 2 * √3 / 4 …
According to the condition of the problem, the radius of the circle described by this triangle is 56.
Using the formula for the area of a triangle in terms of the radius of the circumscribed circle, we can compose the following equation:
a ^ 3 / (4 * 56) = a ^ 2 * √3 / 4,
solving which, we get:
a ^ 3/224 = a ^ 2 * √3 / 4;
a / 224 = √3 / 4;
a = 224 * √3 / 4 = 56√3.
Applying the formula for the area of a triangle in terms of the lengths of its side and the height lowered to this side, we find the height h of this regular triangle:
h = 2 * a ^ 2 * (√3 / 4) / a = 2 * a * √3 / 4 = 2 * 56√3 * √3 / 4 = 112 * 3/4 = 28 * 3 = 84.
Answer: 84.