those three words are one of the most important part of trigonometry.
- sine: the word sine is know as SOH, sine is one of the three formulas in trigonometry. that formula is used to find on of the three angle in right side triangle. to find the angle that you looking for you need to divide the measurement that is opposite to the angle that your trying yo find.
2. cosine: cosine that is also known as CAH is the adjacent side that is being divided by the the hypotenuse of the triangle to get the curtain degree that you are looking for. 
3. tangent: tangent also know as TOA is the opposite side divided by the adjacent side. it is the only formula beside the other two that does not need a hypotenuse as a denominator.