![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
Right triangle, right side is 4cm, 3cm respectively, with a right side as the axis rotation, get a cone, what is the maximum volume?
(1) The results show that a cone with a bottom radius of 3cm and a height of 4cm is obtained by rotating the 4cm right angle side as the axis; the volume is 13 × 3.14 × 32 × 4, = 13 × 3.14 × 9 × 4, = 37.68 (cubic centimeter); (2) a cone with a bottom radius of 4cm and a height of 3cm is obtained by rotating the 3cm right angle side as the axis; the volume is 13 × 3.14 × 42 × 3, = 3.14 × 16, = 50.24 (cubic centimeter) The maximum volume is 50.24 cubic centimeter
How many cubic decimeters is the volume of a cone formed by a right triangle with a base length of 2 decimeters and a rotation of 1 circle on the axis of the line where its height lies?
The square of Wu x 2 is one third of X 3x
There are two cones with equal bottom area. One is 4 decimeters high and 48 cubic decimeters in volume. The other is 3 decimeters high. What is the volume
First of all, it is necessary to make clear the formula for calculating the volume of a cone, the bottom area x H / 3
So according to the height of a cone is 4 decimeters and the volume is 48 cubic decimeters, the area of its bottom is 48x3 / 4 = 36
So the other volume is 36x3 / 3 = 36 cubic decimeters
RELATED INFORMATIONS
- 1. There are two cones with equal ground area. One cone is 4 decimeters high and 48 cubic decimeters in volume. The other cone is 3 decimeters high. What is the volume? (using proportional solution)
- 2. A piece of hard paper of right triangle with two right sides of 3 cm and 6 cm respectively. The volume of three-dimensional figure can be obtained by rotating one right side of it as an axis The maximum is () cubic centimeter?
- 3. A cuboid container with length of 80cm, width of 50cm and height of 30cm is filled with water. Pour the water into a goldfish tank with length of 100cm, width of 60cm and height of 35cm. (1) how long is the distance between the water surface and the tank mouth? (2) how much glass does it need to make such a goldfish tank?
- 4. Triangle ABC, ad is perpendicular to BC, BC intersects at D, ad has a point E, connect be and EC, prove be-ec > bd-dc You can use the difference between the two sides less than the third side to do, Pythagorean theorem has not been learned
- 5. As shown in the figure, △ Abe and △ ACF are equilateral triangles with AB and AC of △ ABC as sides respectively. CE and BF intersect at O (1) to prove: ∠ AEC = ∠ ABF. (2) to find the degree of ∠ BOE
- 6. As shown in the figure, in △ ABC, ﹥ ABC = ﹥ C, ﹥ EBC = ﹥ bed = 60 °, ad bisects ﹥ BAC, proving: ﹥ d = 30 °
- 7. BD bisection angle ABC, be the angle ABC is divided into two parts of 2:5, angle DBE = 21 degrees, find the degree of angle ABC, do not unknown! urgent
- 8. In △ ABC, ∠ ABC = 30 ° with BC and ab as sides, make equilateral △ BCD and equilateral △ ace to connect be Verification: ab & sup2; + BC & sup2; = be & sup2;
- 9. Triangle ABC and ace are equilateral triangles. ① prove: DC = be. ② prove: OA is the angle bisector of ∠ doe
- 10. Given ab ∥ CD, EF ∥ CD, ∠ CDE = 150 ° and ∠ bed = 80 °, calculate the degree of ∠ Abe
- 11. The two right sides of a right triangle are 12 cm and 8 cm respectively. If you rotate along one of the right sides as an axis, you will get a cone. What is the maximum volume of the cone?
- 12. For a right triangle, the two right sides are 6cm and 9cm respectively. After rotating along one right side for a circle, a cone is obtained. What is the volume of the cone?
- 13. The length of three sides of a right triangle is 3, 4 and 5. If each side is rotated for one circle, what geometry is obtained? What are their volumes
- 14. The rectangle with the length of 4cm and the width of 2cm respectively revolves around the straight line where the length and the width lie to get two geometric bodies. Which geometric body has the largest volume and the surface area? Drawing calculation instructions
- 15. If the images of y = - X-B * 2 and y = 2x + 4 intersect at a point of x-axis, a and y-axis intersect at B and C respectively, how to find the angle ABC area
- 16. Known: point a (- 2,0), B (3,0), point C on the Y-axis and the area of △ ABC is 15, find the coordinates of point C
- 17. Is an equilateral triangle a centrosymmetric figure?
- 18. Are equilateral triangles and five pointed stars on the national flag centrosymmetric
- 19. Regular triangle, circle, parallelogram, regular pentagons, which are centrosymmetric figures
- 20. Line segment equilateral triangle in isosceles triangle is both axisymmetric figure and centrosymmetric figure?