All calculation formulas of cylinder and cone

All calculation formulas of cylinder and cone

Cylinder = s base × H = π R & sup2; × h, or the square h of S = π R
The cuboid volume formula is: V length = ABC
The volume formula of cube is v = a · a · a = a ^ 3
Cone = bottom area × height × one third
The formula of sphere volume: v = (4 / 3) π R ^ 3

All the formulas for solving cylinder and cone
Note: all formats are
The area of the bottom of the cylinder is the ratio of the circle to the radius, and the area of the bottom of the cylinder is the ratio of the circle to the radius;

Side area of cylinder = perimeter of bottom circle × height surface area of cylinder = upper and lower bottom area + side area volume of cylinder = bottom area × volume of high cone = bottom area × height △ 3 side area of cone = (circumference × generatrix length × degree of center angle) △ 180 surface area of cone = side area + area of bottom circle s side of straight prism = CH (C

The perimeter ratio of the two circles is 3:2, and the area difference is 10 square centimeters. What is the sum of the areas of the two circles?

2πR:2πr = 3:2,R:r=3:2
Large circle area: small circle area = π R ^ 2: π R ^ 2 = 9:4
(large circle area - small circle area): small circle area = (9-4): 4
10: Small circle area = 5:4
Small circle area = 8
Large circle area: 8 = 9:4
Large circle area = 18
The sum of the areas of the two circles = 18 + 8 = 26 square centimeters
πR^2 - πr^2 = 10
π(3r/2)^2 - πr^2 = 10
(5πr^2)/4 = 10
πr^2 = 8

The radius of a semicircle is a centimeter. What are the perimeter and area of the semicircle

Perimeter = a × 3.14 + 2A = 5.14a cm
Area = a × a × 3.14 × 1 / 2 = 1.57a & # 178; square centimeter

The circumference of a semicircle is 30.84 cm. Can you work out the radius of the semicircle?

6

The radius of a semicircle is 4 decimeters, the circumference of the semicircle is () decimeters, and its area is ()

The radius is 4 decimeters, the diameter is 8 decimeters, the circumference of the whole circle is 3.14 * 8 = 25.12 decimeters, the circumference of the semicircle is 25.12/2 = 12.56 decimeters, the area of the whole circle is 3.14 * 4 * 4 = 50.24 square decimeters, and the area of the semicircle is 50.24/2 = 25.12 square decimeters

The circumference of a semicircle is 10.28 decimeters, the radius of the semicircle is 〔〕, the area is ()?

Radius: 10.28 ÷ (3.14 + 2) = 2 decimeters
Area: 3.14 × 2 & # 178; △ 2 = 6.28 square decimeters

The circumference of a semicircle is 30.84 cm. Find the radius of the semicircle

Let the radius of the semicircle be r cm
2R+2*3.14*R/2=30.84
2R+3.14R=30.84
5.14R=30.84
R=6

Cut the disc with circumference of 18.84cm into two semicircles of the same size. The circumference of each semicircle is______ cm．

18.84 △ 3.14 + 18.84 △ 2, = 6 + 9.42, = 15.42 (CM); answer: the circumference of each semicircle is 15.42 cm

It is known that the circumference of a circle is 18.84cm. How to find the diameter and radius, it's best to have a formula. Another way is that the circumference of a circle is 37.68dm
It's better to be more detailed and have a formula

Because the formula, circumference = pie D (D is diameter), because pie is a fixed value of 3.14, so when circumference = 18.84, d = 18.84 △ 3.14 = 6, radius = 6 △ 2 = 3, the solution to the second problem is the same, d = 3.768 △ 3.14 = 12, radius = 12 △ 2 = 6