Formulas From Geometry

Triangle

Area= (1/2)bh     b-base     h-height

Height of a triangle can be found by h=a sin ø

Right Triangle

Pythagorean Theorem :  c2= a2 + b2

Parallelogram

Area= bh

Trapezoid

Area= h/2 (a+b)

Circle

Area = π r2

Circumference = 2πr

Sector of a Circle

Area= ør2/2

s=rø

(ø is measured in radians, not degrees)

Circular Ring

Area= π( R^2- r 2)

 =2πpw

(p= average radians

w= width of ring)

Cone

(A= area of base)

Volume = Ah/3

Sphere

Volume= 4/3πr3

Surface Area= 4πr2