Karra's Surface Area Growing Post

Rectangular Prism

Top :

A=lxw

12x4.5

54x2

108cm2

Side:

A=lxw

4.5x 21

94.5x2

189cm2

Front:

A=lxw

12x21

252x2

504cm2

TSA=504+108+189 =
= 801 cm2

Cylinder

R=d/2
= 2.4x2
= 1.2

C=3.14xd
= 3.14x2.4
= 7.536

A= 3.14 x r x r
= 3.14 x 1.2 x 1.2
= 4.5216

TSA= 7.536+4.5216+75.36 =
= 87.4176 cm2

Triangular Prism
















bxh/2
5x7/2
=17.5

bxh/2
5x7/2
=17.5

lxw
9x12
= 108

lxw
9x7
= 63

lxw
5x9
= 63


TSA = 63+63+108+17.5+17.5
=269 cm2

For triangular Prism I missed a number, so the number that is missing is 9!