### Elegant Algebraic Equations

Sunday, October 18, 2009
Elegant Algebraic equations.

I didn't know what Mr. Backe was talking about when he said Elegant Algebraic Equations. And thats what they are, the most elegant way to find the surface area of a shape. So im going to tell you the different formulas for different shapes.

S.A of a Cube 6s²

Say the cubes side lenght is 7

S.A 6s²

S.A = 6(7²)

S.A = 6(49)

S.A= 294 u²

A rectangular Prism

S.A 2(lw)+ 2(hw) + 2(hl)

S.A 2 (4)(6) + 2 (5)(6) + 2(5)(4)

S.A 2 (24)+ 2(30)+ 2(20)

S.A 48+ 60+40

S.A 148u²

Cylinder

S.A 2pi r² + 2 pi rh

S.A 2 (3.14)(5²) + 2(3.14)(5)(20)

S.A 2(3.14)(25)+ 2(3.14)(100)

S.A 2 (78.539) + 2 (314.159)

S.A 157.078 + 628.318

S.A 785.396 u²

Triangular Prism

2 Triangles bh ( don't put divided by 2 because bh/2 is for one triangle I am finding for 2)

2 triangles (15)(10)

2 triangles 150u²
base of prism lw

base of prism (15)(20)

base of prism 300u²

2 roofs lw

first we need the side of the roof.

a² + b² = c²

10²+ 15²=c²

100+ 225 = c²

(sqroot)325= (sqroot)c²

18.027 = c

2 roofs lw

2 roofs (20) (18.027)

2 roofs 360.555 u²

150u² + 300u² + 360.555 u²=

810.555u²

kristin9-05 said...

Great post! I really liked your use of colors and pictures. You explained things very well. :)

melanie905 said...

Good job Shaneille! Nice colours and explanations. Although, you should add more pictures. And don't forget the "units" after each measurement. But overall, great post!

Lissa 9-05 said...

Good job Shaneille ! I like your colours and how your pictures are clear to see. Keep up with the great posts!