Aproximations

p

√1

√2

√3

p ≈ 3.14

√1 = 1

√2 ≈ 1.4

√3 ≈ 1.7

Area of a triangle

Base x Height

__________

2

Pythagorean Theorem

Determining lengths of a right triangle

IF 

a = one side of right angle

b= other side of right angle

c = hypotenuse (side opposire right angle)

a² + b² = c²

Frequently used Pythagorean triangles:

3, 4, 5 triangles or multiples

 of those numbers

A right isosceles triangle

has the following proportions:

If the sides of the right triangle are a & b, and the hypotenuse is c...

a = x

b = x

c = √2(x)

A 30, 60, 90 triangle has

the following proportions

side across from 30^o = x

side across from 60^o = x√3 

hypotenuse = 2x

Area of a circle =

pr²

Circumference of a circle =

2pr

^or

pd