Q. Into how many degrees is a circle divided?

A. 360.

Q. How is each degree divided in the U. S. Artillery service?

A. Each degree is divided into one hundred equal parts.

Q. Define a circle.

A. A circle is a plane figure bounded by a curve, every point of which is equally distant from a point within called the center. Fig. 57 represents a circle with A as the center.

Q. What is the vertex of an angle?

A. The point where the two intersecting lines cross. As in Fig. 57, A is the vertex of the angle SAX.

Q. Define an azimuth angle.