Surface area - 9th grade (14y) - examples
- Octahedron - sum
On each wall of a regular octahedron is written one of the numbers 1, 2, 3, 4, 5, 6, 7 and 8, wherein on different sides are different numbers. For each wall John make the sum of the numbers written of three adjacent walls. Thus got eight sums, which also.
- Tetrahedral pyramid
What is the surface of a regular tetrahedral (four-sided) pyramid if the base edge a=23 and height v=8?
Cylinder shell has the same content as one of its base. Cylinder height is 25 m. What is the radius of the base of the cylinder?
- Volume from surface area
What is the volume of the cube whose surface area is 96 cm2?
- Cylinder - A&V
The cylinder has a volume 253. The base has a radius 5. What is the area of surface of the cylinder?
The cylinder surface is 139 dm2, its height is equal to the radius of the base. Calculate height of this cylinder.
- Rotary cylinder
The rotating cylinder has a surface area 69.08 cm2. The area of the shell is 62.8 cm 2. What is the diameter of the cylinder?
How much metal is needed for production 37 pieces of gutter pipes with the diameter 16 cm and length of 1 m? The plate bends add 7% of the material.
- Pyramid roof
1/3 of area of the roof shaped regular tetrahedral pyramid with base edge 10 m and height of 4 m is already covered with roofing. How many square meters still needs to be covered?
- Sphere A2V
Surface of the sphere is 306 m2. What is its volume?
- Prism X
The prism with the edges of the lengths x cm, 2x cm and 3x cm has volume 48000 cm3. What is the area of surface of the prism?
Find the cuboid that has the same surface area as the volume.
- Triangular prism
Calculate the surface area and volume of a triangular prism, base right triangle if a = 3 cm, b = 4 cm, c = 5 cm and height of prism h=12 cm.
- Cube volume
The cube has a surface of 384 cm2. Calculate its volume.
- 3sides prism
The base of vertical prism is an isosceles triangle whose base is 10 cm and the arm is 13 cm long. Prism height is three times the height of base triangle. Calculate the surface area of the prism.
The top of the tower is a regular hexagonal pyramid with base edge 9.2 meters long and a height 9.6 meters. How many m2 of sheet is required to cover the top of the tower if we count 12% of the sheet waste?
Three metal balls with volumes V1=41 cm3 V2=58 cm3 and V3=83 cm3 melted into one ball. Determine it's surface area.
How many CZK we pay for lining the perimeter walls of the bathroom with rectangular shape with dimensions 3.5 m and 4 m, high 1.5 m if 1 square m tile cost 300 CZK?
- Cylinder - basics
Cylinder with base radius r = 37 cm and height h=74 cm. Calculate:
- Surface area 2
Calculate how many % reduce the surface area of the cube is we reduced length of each edge by 10%.