Angle (degree)：練習問題

Which of the following is the unit used to measure the size of an angle?

In the figure, \(∠AOB\) is a straight angle. If \(∠AOC = 55^{\circ}\), find the size of \(∠COB\).

In a triangle, if one angle is \(40^{\circ}\) and another angle is \(50^{\circ}\), what is the measure of the third angle?

What is the size of a round angle in degrees?

If the sum of two angles is equal to a round angle, and one of the angles is \( 135^{\circ} \), what is the size of the other angle?

In geometry, how many degrees are there in four right angles added together?

In the diagram, points A, O, and B lie on a straight line. If \(\angle AOC\) is a right angle and \(\angle COD = 25^{\circ}\), what is the size of the acute angle \(\angle DOB\)?

Point \(O\) is a point on a straight line \(PQ\). If a ray \(OR\) is drawn such that \(\angle POR\) is \(35^\circ\), find the size of the reflex angle \(\angle POR\).

Observe the provided figure of a circle with center \(O\).
(a) What is the name of the angle formed by a complete turn around the center?
(b) What is the size of this angle in degrees?

In the diagram, three angles meet at a point on a straight line. Angle \(A\) is an acute angle of \(42^{\circ}\). Angle \(B\) is a right angle.
(a) Find the size of the third angle, Angle \(C\).
(b) Is Angle \(C\) an acute, obtuse, or right angle?