When determining the designate angle we can use different ratios of sides.

• We can use a ratio of the opposite to the hypotenuse.
• We can use a ratio of the adjacent to the hypotenuse.
• We can use a ration of the opposite to the adjacent.

Each ratio has a trigonometric function that helps turn the ratio into an angle.  They are:

• sin θ = opposite/hypotenuse
• cos θ = adjacent/hypotenuse
• tan θ = opposite/adjacent

One way of remembering the ratios are these mnemonics:

• SOH – Sine is opposite/ hypotenuse
• CAH – Cosine is adjacent/hypotenuse
• TOA – Tangent is opposite/ adjacent

By the way,

• sin is short for sine
• cos is short for cosine
• tan is short for tangent

Attributions

Trigonometry (Part one).video by The Electric Academy is under a Creative Commons Attribution Licence.

Trigonometry (Part two).video by The Electric Academy is under a Creative Commons Attribution Licence.