f. If one radius is held stationary and the other is moved 360, it will return to its original

direction without increasing or decreasing the magnitude of the angle. This principle, after adding 360

to the minuend, will allow you to perform straight subtraction.

surveying, map making, map reading, astronomy, navigation, and many other engineering subjects

where objects are represented by drawn figures or are given exact locations. Trigonometry primarily

deals with measuring angles and distances. As a surveyor, you will be apply the principles for solving a

right triangle to obtain the indirect measurement of angles and distances.

a. In Figure 4-1, note that the triangle's angles are identified by capital letters, and the sides

opposite each angle are identified by the same letter only in small print. A general method of

identifying the sides of a right triangle is by giving them names in reference to the angles. Referring to

the acute angle A in Figure 4-1, side a is known as the side opposite and side b is known as the side

adjacent. With reference to the acute angle B, side b is the side opposite and side a the side adjacent.

The side opposite the right angle (c in this case) is always known as the hypotenuse.