VOLUME OF 3D OBJECTS

8 STE-B

presentation of group 4

Volume

The students will have a better understanding of three-dimensional objects.

The student will have a better awareness of why they need to use the volume equation (l x w x h).

The student will be able to identify cubes all around them.

The students will be able to find the volume of cubes.

Objectives

• The amount of space that a substance or subject occupies, or that is enclosed within a container.
• It is known as the capacity of an object.

What is volume?

finding the volume of a

cube

volume= 12 x 12 x 12 volume= 1728 cm³

If one side of a cube is 12cm. Find the volume of the cube.

EXAMPLE 2

volume= 125 cm³

volume= 5 x 5 x 5

volume= side x side x side

side 1= 5 cm side 2= 5 cm side 3= 5 cm

Note: each side of a cube is congruent.

If one side of a cube is 5 cm. What is the volume?

EXAMPLE 1

HOW TO FIND THE VOLUME OF A 3D SHAPE

finding the volume of a

Rectangularprism

volume= 12cm x 6 cm x 8cmvolume= 576 cm³

volume= length x width x height

Note: volume= length x width x height

6 cm

8cm

12cm

If the length of a shoebox is 12cm, it's width is 6cm, and it's height is 8 cm. What is the volume of the shoebox?

EXAMPLE 3

finding the volume of a

cylinder

=78.5 x 7 cm =549.5 cm³

then, multiply the height to get the volume.

solution: 3.14 x radius² =3.14 x 5 x 5 =78.5 cm²

5 cm

7 cm

A tin can has a height of 7 cm, and a radius of 5 cm. Find the volume.

Finding the volume of a cylinder

EXAMPLE 4

finding the volume of a

triangularprism

3 ft

5 ft

6 ft

Volume = 45 ft³

Volume = 90/2

Volume = 5 x 3 x 6 x 1/2

Volume = L x W x H x 1/2

A tent has a length of 5ft, a width of 3ft , and a height of 6ft .Find the volume of the tent.

Finding the volume of a triangular prism

EXAMPLE 5

finding the volume of a

CONE

Finding the volume of a Cone

Example 6

A cone has a height of 18 cm and a radius of 8 cm. Find the volume of the cone.

=384(3.14) cm³

=1205.76 cm³

=1/3π(64cm)²(18cm) = 384π cm³

= 1/3π (8cm)²(18cm)

V = 1/3 πr²h

8cm

18 cm

find the volume of a

SPHERE

Finding the volume of an Sphere

A sphere has a radius of 6 cm . Find the volume of the given sphere

904.32 mm³

2712.96/3

4 x 3.14 x 216

Example 7

6 cm

(4 x 3.14 x 6³)/3

4πr³/3

Thank you!