3-D shapes.

Mathematics for Js13rd Term.

Theme: Mensuration and Geometry.

Week 3&4.

3-D shapes.

Performance Objectives.

Students should be able to

1. Identify the properties of cubes and cuboids.

2. Identify the properties of pyramids and cones.

3. Identify the properties of cylinders and spheres.

4. Find the volume of cubes and cuboids.

CUBES AND CUBOIDS.

Cube	Cuboid
It has six square flat faces	It has six rectangular flat faces
It has twelve edges	It has twelve edges
It has eight vertices	It has eight vertices.

 

 

CONE AND PYRAMID.

Properties of Cone and pyramid

Cone	Pyramid
One vertex	Faces depend on their bases
One curved surface	Number of sides determines the number of faces
One circular flat face	Number of sides of the base determines the number of edges.
One circular edge

 

CYLINDER AND SPHERES.

Properties of a cylinder.

1.Two circular flat faces.

2. One curved face.

3. Two circular edges.

4. No vertex.

Sphere has no edges and vertices, but a spherical surface.

PERIOD 2

Content.

The volume of solids is a measure of the amount of space it occupies. A solid object is also called a 3-dimensional object. The cube is used as the basic shape to estimate the volume of a solid.

When the edges of a cuboid are equal it is called cube.

Example 1: Find the volume of a cuboid 3cm,8cm and 5cm.

V=3x5x8=120cm³.

Example: Find the area of a cuboid with 7cm as sides.

V=7x7x7

=343cm³.