All Common Core: 8th Grade Math Resources
Example Questions
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 #494 : Grade 8
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 #3 : 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 #181 : Geometry
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 #101 : Solid Geometry
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:
Example Question #182 : Geometry
Give the volume of a cone whose height is 10 inches and whose base is a circle with circumference inches.
A circle with circumference inches has as its radius
inches.
The area of the base is therefore
square inches.
To find the volume of the cone, substitute in the formula for the volume of a cone:
cubic inches
Example Question #183 : Geometry
The height of a cone and the radius of its base are equal. The circumference of the base is inches. Give its volume.
A circle with circumference inches has as its radius
inches.
The height is also inches, so substitute in the volume formula for a cone:
cubic inches
Example Question #184 : Geometry
In terms of , give the volume, in cubic inches, of a spherical water tank with a diameter of 20 feet.
20 feet = inches, the diameter of the tank; half of this, or 120 inches, is the radius. Set , substitute in the volume formula, and solve for :
cubic inches
Example Question #185 : Geometry
A sphere has diameter 3 meters. Give its volume in cubic centimeters (leave in terms of ).
The diameter of 3 meters is equal to centimeters; the radius is half this, or 150 centimeters. Substitute in the volume formula:
cubic centimeters
Example Question #11 : Volume Of A Three Dimensional Figure
A cone has a radius of inches and a height of inches. Find the volume of the cone.
The volume of a cone is given by the formula:
Now, plug in the values of the radius and height to find the volume of the given cone.