Basic Technical Mathematics, 11th Edition

2.4 Circles

• Properties of Circles • Tangent Secant Lines • Circumference Area • Circular Arcs Angles • Radian Measure of an Angle

The next geometric figure we consider is the circle. All points on a circle are at the same distance from a fixed point, the center of the circle. The distance from the center to a point on the circle is the radius of the circle. The distance between two points on the circle on a line through the center is the diameter. Therefore, the diameter d is twice the radius r, or $d\hspace{0.17em}=\hspace{0.17em}2r\hspace{0.17em}.\hspace{0.17em}$ See Fig. 2.76.

Fig. 2.76

There are also certain types of lines associated with a circle. A chord is a line segment having its endpoints ...