Aim: How do you find the surface area and volume of a sphere?
April 18, 2012


Spheres: A Sphere is the set of all points in space equidistant from a given point called the center.

Volume:                                                                                       Surface Area:

                                      



Surface Area:

Aim: How do we find the volume of pyramids and cones?
April 17, 2012

Volume of a Pyramid

A pyramid has a base and triangular sides which rise to meet at the same point. The base may be any polygon such as a square, rectangle, triangle, etc. The general formula for the volume of a pyramid is:

Area of the base * Height * 1/3

The volume of a pyramid with a rectangular base is equal to: 

Length_of_base * Width_of_base * Height * 1/3

                                           

Volume of a Cone

The volume of a cone is 1/3(Area of Base)(height) = 1/3 π r² h

                                          

Aim: How do we find surface area and lateral area of prisms and cylinders?

A faster way to find lateral area:

L.A = ph

Surface area = lateral area + area of the bases
 ( S.A = L.A + 2B)

The surface area of a prism = 2 × area of base  +  perimeter of base × H

The actual formula used to find the surface area will depend on the shape of the base of the prism.

Aim: How do we identify polygons?
April 02, 2012




 Solid Geometry
Solid geometry is the geometry of the 3-dimensional space.
It is called three-dimensional, or 3D because there are three dimensions width, depth and height.

Properties:
Solids have properties, such as
- volume
- surface area

There are two main types of solids, "polyhedra" and "non-polyhedra"

Polyhedra- They must have have flat faces
 - prisms , pyramids , and platonic solids

Non-polyhedra- if any surface is not flat.
- sphere , cylinder and cone

Prisms: A prism has the same cross section all along its path/length.

Cross sections : A cross section is the shape you get when cutting straight across an object.

A prism is a solid with bases that are 2 congruent polygons. The other sides of the prism are called the lateral faces.

A prism is named by the shape of its base.