Gordon Boyds surface Area Growing Post Macrh 7 2010

* = Squared

Rectangular Prism

To calculate the surface area of a Rectangular Prism you simply calculate the area of 3 sides and add 2 of each of the answers.

Side 1 Side 2 Side 3

L × W = A L × W= A L × W = A

4 × 3 = A 3 × 6 = A 4 × 6 = A

12cm* = A 18cm* = A 24cm* = A

SA = 12cm*+12cm*+18cm*+18cm*

+24cm*+24cm*

SA = 108cm*

Triangular Prism

To calculate the area of a Triangular Prism you calculate the area of the triangle and the 3 rectangles and add it all together.

Triangular Side Rectangular Side 1 Rectangular Side 2

(b × h) ÷ 2 = A L × W = A L × W = A

(2 × 2) ÷ 2 = A 5 × 3 = A 5 × 2 = A

2cm* = A 15cm* = A 10cm* = A

SA = 2cm*+2cm*+15cm*+15cm*+10cm*

= 44cm*

Cylinders

Calculating the surface area of a Cylinder is by far the easiest as it can be done in only 2 formulas.

r = d ÷ 2 SA = 2 × (Pi × r*) + (Pi × d × h)

r = 4 ÷ 2 = 2 × (3.14 × 2*) + (3.14 × 4 × 7)

r = 2 = 200.96cm*

And here's a video that also demonstrates how to calculate surface area