An Introduction to Triangle Trigonometry

Okay, here we are, basic triangle trigonometry.  Here are a few things that will come in handy:

Trigonometric Properties:

SOH CAH TOA 

sine=((opposite)/(hypotenuse))

cosine=((adjacent)/(hypotenuse))

tangent=((opposite)/(adjacent))

And the less commonly used: CHO SHA CAO

cosecant=((hypotenuse)/(opposite))

secant=((hypotenuse)/(adjacent))

cotangent=((adjacent)/(opposite))

~ Use the functions above when solving for a side

~ Use the inverses of the functions above when solving for an angle.

Naming Parts of a Triangle:

A triangle’s sides are labeled as lowercase letters.

A triangle’s edges are labeled as either capital or greek letters (alpha, beta, gamma, delta, phi, psy, omega, theta, etc).

Geometric Properties:

The sum of the angles of a triangle add up to 180°. In other words, if you know 2 angles of a triangle you can subtract those from 180 to find the third angle!

The sum of the angles of any polygon with 4 or more sides add up to 360°.

Hope this helps!