The chord AB divides the circle with the center O into two arcs. Determine the degree measure of the central angle
The chord AB divides the circle with the center O into two arcs. Determine the degree measure of the central angle corresponding to the arc AB, if the ratio of the degree measures of the arcs is …
We denote the degree measure of the smaller arc AB through 2 * X0, then the large arc AB is equal to 7 * X0.
The degree measure of a full circle is 360, then (2 * X + 7 * X) = 360.
9 * X = 360.
X = 360/9 = 40.
Then the degree measure of the smaller arc AB = 2 * 40 = 80.
The central angle of the AOB is equal to the degree measure of the arc on which it rests. Angle AOB = 80.
Similarly:
3 * X + 5 * X = 360.
8 * X = 360.
X = 360/8 = 45.
Arc AB = 3 * 45 = 135.
Angle AOB = 135.
7 * X + 11 * X = 360.
18 * X = 360.
X = 360/18 = 20.
Arc AB = 7 * 20 = 140.
Angle AOB = 140.
Answer: Angle AOB is equal to: a) 80, b) 135, c) 140.