The axial section of the cone is an equilateral triangle with an apex angle of 120. The generatrix of the cone is 6cm
January 12, 2021 | education
| The axial section of the cone is an equilateral triangle with an apex angle of 120. The generatrix of the cone is 6cm. find the volume a ball circumscribed about a cone.
Triangle ABC is isosceles with an apex angle B = 120.
The height BO1 of the triangle ABC is also its median and bisector, then the angle ABO1 = 120/2 = 60.
From the point O, the center of the sphere, we construct its radius OA and OB.
In triangle AOB, side OA = OB = R, then triangle AOB is isosceles, and since angle ABO = ABO1 = 60, then triangle AOB is equilateral, OA = OB = R = AB = 6 cm.
Let us determine the volume of a sphere described about a cone. V = 4 * π * R3 / 3 = π * 288 cm3.
Answer: The volume of the ball is π * 288 cm3.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.