MATH  RESOURCES Part 2

Triangles, more triangles, and yet even more triangles...

It's important to be well versed in triangle formulas. The Pythagorean theorem, triangle inequality, area of a triangle and the trigonometry associated with triangles are must haves to be versatile on the math exams. Let's take a look at some of the formulas. [Notes: The ability to illustrate triangles on Geocities is next to nothing. I apologize for the lack of a drawing however I will try to demonstrate with solid clean numbers what you should already know]

Pythagorean Theorm

Probably one of the most widely used theorems in math. This one allows you solve for a missing side of a triangle if at least two are given. THIS WILL ONLY WORK ON RIGHT TRIANGLES!! All else will have to resort to the law's of sine and cosine, which aren't as "friendly"

Triangle Inequalities

a + b > c

Just a small reminder that all three legs of a triangle must reach each other. Common sense really. If you have two sides whose lengths are 4 and 5, naturally the third side must be less than 9 otherwise the other two sides wouldn't make up the difference and you'd have a flat surface!

Area of a Triangle

1/2 b h

Tell me you knew that already...

Area of an Equilateral Triangle

Basic Trig Functions

Sine:        opposite / hypotenuse Cosine:    adjacent / hypotenuse Tangent   opposite / adjacent

s^2<3>     4

This is an extended version of the area of a triangle. It's just in a derived form. Same thing, just in a different way. That's "side squared times the square root of 3, all over four".

Example Angle C:              Angle A:                        Sine = c / b         Sine = a / b Cosine = a / b     Cosine = c / b Tangent = c / a   Tangent = a / c

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A

More Math ------>>

b

c

B

C

a

Gotta' love my pitiful triangle...