Introduction. Trigonometry is a branch of mathematics that uses triangles to help you solve problems.Trig is useful to surveyors, engineers, navigators, and machinists (and others too.). Topic 1. Labeling Right Triangles. Labeling Right Triangles. The most important skill you need right now is the
1. Introduction to Trigonometry Right Triangle Trigonometry
2. Introduction Trigonometry is a branch of mathematics that uses triangles to help you solve problems.
Trig is useful to surveyors, engineers, navigators, and machinists (and others too.)
4. Labeling Right Triangles The most important skill you need right now is the ability to correctly label the sides of a right triangle.
The names of the sides are:
the opposite side
the adjacent side
5. Labeling Right Triangles The hypotenuse is easy to locate because it is always found across from the right angle.
6. Labeling Right Triangles Before you label the other two sides you must have a reference angle selected.
It can be either of the two acute angles.
In the triangle below, letís pick angle B as the reference angle.
7. Labeling Right Triangles Remember, angle B is our reference angle.
The hypotenuse is side BC because it is across from the right angle.
10. Labeling Right Triangles Letís put it all together.
Given that angle B is the reference angle, here is how you must label the triangle:
11. Labeling Right Triangles Given the same triangle, how would the sides be labeled if angle C were the reference angle?
Will there be any difference?
12. Labeling Right Triangles Angle C is now the reference angle.
Side BC is still the hypotenuse since it is across from the right angle.
16. Labeling Practice Given that angle X is the reference angle, label all three sides of triangle WXY.
Do this on your own. Click to see the answers when you are ready.
17. Labeling Practice How did you do?
Click to try another one...
18. Labeling Practice Given that angle R is the reference angle, label the triangleís sides.
Click to see the correct answers.
19. Labeling Practice The answers are shown below: