|
Farber Math 140
Useful Formulas
Plane Geometry (2D)
Right Triangle- (Pythagorean Theorem):
If c is the hypotenuse and a and b are the other sides
then 
Similar Triangles: Corresponding sides are in proportion.
| 2D Geometry |
Area |
Circumference (perimeter)
|
| Triangle: |
A = 1/2bh |
P = a + b+ c |
| Equilateral triangle: |
h =  s , A =  s2 |
P = 3s |
| Rectangle: |
A = lw |
P = 2l +2w |
| Parallelogram |
A = bh |
P = 2l +2w |
| Trapezoid: |
A = 1/2h(a + b) |
|
| Circle: |
A = πr2 |
C = 2πr |
| Solid Geometry 3D |
Volume |
Surface Area |
| Rectangular box: |
V = lwh |
S = 2 ( hl +lw + hw) |
| Sphere: |
V =  π
r3 |
S = 4 πr2 |
| Right Circular Cylinder: |
V = πr2h |
S = 2πrh + 2 πr2 |
| Right Circular Cone |
V = 1/3 πr2h |
S = πr |
Analytic Geometry : Distance between points (x1 , y1)
and (x2 , y2) s= 
From Trigonometry :
Double Angle Formulas: sin 2u = 2 sin u cos u
and cos 2u = cos2 u - sin2 u = 1 - 2 sin2 u
= 2 cos 2 u - 1
| 
