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.
PART B - TRIGONOMETRIC FUNDAMENTALS
4-4. Functions of Acute Angles. Understanding trigonometric fundamentals is essential to studying
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.
Figure 4-1. Triangle relationships