Math Review

Area & Perimeter

Perimeter
Add up all the sides (measurements) together
* Remember for perimeter answer using whatever unit is used in the question.

Area of 2D Polygons
L (length) x W (width)
is the formula for all polygons (a closed 2D shape that has sides made form straight line segments)

Area of a Parallelogram



Area of a 2D Triangle
B (base) x H (height) ÷ 2
*Always remember to include the units (cms, m, kms)!!!  You must remember to include a ² for surface area.

 Surface Area of a Rectangular Prism (3D Shape)

• Remember 3D shapes have faces!
• Label the shapes opposite faces A, B, C (just like we did in class)

L x W x 2
Then add up all of the surface areas
* For surface area you need to include a ² as part of your units

Finding Surface Area of a Triangular Prism
1.     Label faces (A, B, C, D).  *  Remember that only the triangles faces will be labelled A, all other faces may be different measurements, so they need to be labelled separately (as B,C,D) just like we did in class.
2.     Find the surface area of the triangular face (B x H) ÷ 2 x 2 (because there are two triangular faces)
3.     Find the surface area of each of the remaining faces (B,C, D)
L x W  (for each of the remaining faces)
4.     Add up all of the surface areas
* For surface area of a triangular prism you need to include a ² as part of your units

Volume