Skill: Draw angles with a protractor

An angle measures the amount of turn between two rays that share a vertex. A protractor helps you measure and draw angles from $(0^\circ)$ to $(180^\circ)$.

Example: Draw a $(65^\circ)$ angle

1. Draw the first ray.
   Draw a straight ray from a point. Label its endpoint $V$. This point is the vertex.

2. Place the protractor.
   Put the protractor’s center point exactly on $V$. Line up the protractor’s straight edge with the ray.

3. Choose the correct scale.
   Look at the two sets of numbers on the protractor. Use the scale that starts with $(0^\circ)$ along the ray you drew. Do not automatically use the outside numbers.

4. Find $(65^\circ)$.
   On the correct scale, find $(65^\circ)$. Make a small mark there.

5. Draw the second ray.
   Remove the protractor. Use a ruler to draw a ray from $V$ through the mark.

The two rays now form an angle measuring

$$65^\circ.$$

Because $(65^\circ)$ is less than $(90^\circ)$, the angle is acute. A $(90^\circ)$ angle is right, and an angle greater than $(90^\circ)$ but less than $(180^\circ)$ is obtuse.

Check: The vertex should be at the protractor’s center, the first ray should line up with $(0^\circ)$, and the second ray should pass through the number you were asked to draw.