How to use a half-circle protracter by ab

Estimate whether the angle is an acute, obtuse, or right. You look at the arc to see what your considering.

The 0 degree mark to the 180 degree mark is called the baseline. The midline of the baseline is where you line up the vertex.

Put the center of the protractor over the vertex of the angle and make sure that one side of the angle on the baseline

Find the place where the other side of the angle and make sure that the one side of the angle on the baseline.

Decide which of the 0 degree to the 180 degree scale to use. If the angle is an acute use the smaller side, it the angle is an obtuse than use the greater side.

Now we are going to draw angles

Draw a ray.

Place the center of the protractor at the end of the ray. Make sure the ray is aligned with the baseline of the protractor.

Use the scale that shows 0 degrees where the ray crosses the end of the protractor.

Draw a dot where the other ray should cross the edge of the protractor.

Draw a ray from the vertex through the dot.