1. A right triangle, the length of the two right sides are 6 cm and 8 cm respectively, with a right side as the axis, rapid rotation, you can get a cone, what is the maximum volume of the cone? 2. A cylindrical timber is 3 meters long. After it is cut into two small columns, the surface area increases by 12.56 square decimeters. What is the volume of the original column?

1. A right triangle, the length of the two right sides are 6 cm and 8 cm respectively, with a right side as the axis, rapid rotation, you can get a cone, what is the maximum volume of the cone? 2. A cylindrical timber is 3 meters long. After it is cut into two small columns, the surface area increases by 12.56 square decimeters. What is the volume of the original column?

1. In order to maximize the volume of the cone, it is necessary to take 8 cm as the bottom radius, that is, to take 6 cm as the axis to rotate. Bottom area = 3.14 × (8 △ 2) & # 178; = 50.24 (square centimeter) volume = 1 / 3 × 50.24 × 6 = 100.48 (cubic centimeter) 2, 3 M = 30 decimeter, bottom area = 12.56 △ 2 = 6.28 (square centimeter)