For example

1st layer = 4 x 3 = 12 cubes

Total layers = 3

∴ Volume = 12 x 3 = 36 cu. Cm

But this method is not accurate. So we use a formula to find the Volume-rectangular prism.

Volume of Rectangular Prism = l x w x h |

1) A swimming pool is of length 25 m x 10 m x 3 m. The water is filled up to a depth of 2.5 meters. What is the quantity of water in the pool in kilo- liter and liter.

Volume = l x w x h

⇒ 25 x 10 x 2.5 = 625 m

1 kl = 1 m

And 1kl = 1000 l ∴ 625 m

________________________________________________________________

2) The dimensions of a rectangular prism are in the ratio 5 : 3 : 2. Its volume is 21870 cm

Volume = V = 5x X 3x X 2x

⇒ 30x

x

x

x = cube root of (729)

x = 9

∴ Dimensions are, length = 5x = 5(9) = 45 cm

Width = 3x = 3(9) = 27 cm and height = 2x= 2(9) = 18 cm

∴ Total surface area = 2 (lw + wh + lh)

= 2 ( 45 x 27 + 27 x 18 + 45 x 18)

= 2 x 2511

Total surface area = 5022 cm

________________________________________________________________

3) The area of the floor of a room is 67.5 m

Volume = 270 m

Volume =

270 = 67.5 x h

∴ h = 270 / 67.5

∴ h = 4 cm.

• Volume Formulas

• Volume of Irregular Shape

• Volume of Cube

• Volume of Rectangular Prism(Cuboid)

• Volume of Cylinder

• Volume of Cone

• Volume of Sphere

• Volume of Hemisphere

• Volume of Prism

• Volume of Pyramid

8th grade math

Home Page

GMAT

GRE

1st Grade

2nd Grade

3rd Grade

4th Grade

5th Grade

6th Grade

7th grade math

8th grade math

9th grade math

10th grade math

11th grade math

12th grade math

Precalculus

Worksheets

Chapter wise Test

MCQ's

Math Dictionary

Graph Dictionary

Multiplicative tables

Math Teasers

NTSE

Chinese Numbers

CBSE Sample Papers