All Common Core: 8th Grade Math Resources
Example Questions
Example Question #2 : How To Find The Volume Of A Cylinder
Find the volume, in cubic inches, of a cylinder that has a radius of inches and a height of inches.
The formula to find the volume of a cylinder is .
Now, plug in the given numbers into this equation.
Example Question #731 : Geometry
Find the volume of the cylinder if the circular base has an area of , and the height of the cylinder is also .
Write the formula for volume of a cylinder.
Remember that area of a circle is
Since the area of the circle is known, substitute the area into the formula.
Example Question #491 : Grade 8
A car dealership wants to fill a large spherical advertising ballon with helium. It can afford to buy 1,000 cubic yards of helium to fill this balloon. What is the greatest possible diameter of that balloon (nearest tenth of a yard)?
The volume of a sphere, given its radius, is
Set , solve for , and double that to get the diameter.
The diameter is twice this, or 12.4 yards.
Example Question #492 : Grade 8
The diameter of a sphere is . Give the volume of the sphere in terms of .
The diameter of a sphere is so the radius of the sphere would be
The volume enclosed by a sphere is given by the formula:
Example Question #493 : Grade 8
A spherical balloon has a diameter of 10 meters. Give the volume of the balloon.
The volume enclosed by a sphere is given by the formula:
where is the radius of the sphere. The diameter of the balloon is 10 meters so the radius of the sphere would be meters. Now we can get:
Example Question #3 : Volume Of A Three Dimensional Figure
The volume of a sphere is 1000 cubic inches. What is the diameter of the sphere.
The volume of a sphere is:
Where is the radius of the sphere. We know the volume and can solve the formula for :
inches
So we can get:
Example Question #621 : Geometry
A sphere has a diameter of inches. What is the volume of this sphere?
To find the volume of a sphere, use the following formula:
, where is the radius of the sphere.
Now, because we are given the diameter of the sphere, divide that value in half to find the radius.
Now, plug this value into the volume equation.
Example Question #2 : How To Find The Volume Of A Sphere
What is the volume of a sphere with a diameter of ?
Write the formula for the volume of the sphere.
The radius is half the diameter, which is five. Substitute the value.
Example Question #494 : Grade 8
A cone has height 18 inches; its base has radius 4 inches. Give its volume in cubic feet (leave in terms of )
Convert radius and height from inches to feet by dividing by 12:
Height: 18 inches = feet
Radius: 4 inches =
The volume of a cone is given by the formula
Substitute :
Example Question #495 : Grade 8
A cone has height 240 centimeters; its base has radius 80 centimeters. Give its volume in cubic meters.
Convert both dimensions from centimeters to meters by dividing by 100:
Height: 240 centimeters = meters.
Radius: 80 centimeters = meters.
Substitute in the volume formula: