Q&A for How to Make Angles in Math Using a Protractor

The type of angle is not determined by which way it opens. An angle is either acute, right, or obtuse, no matter which way it opens. All that matters is the size of the angle. For example, you can draw a 45 degree angle opening to the left, or opening to the right. Either way, it is an acute angle.

Use the outside, curved edge.

If you're referring to a central angle, draw a diameter. Line up the bottom of the protractor with the diameter so that the midpoint of the protractor aligns with the center of the circle. Use the protractor to draw any central angle up to 180°, using another diameter (or radius) to complete the angle.

Yes, if each side of a triangle is congruent with (the same length as) a side of another triangle, the two triangles are congruent.

A 180° angle forms a straight line. The vertex of the angle can be considered to be any point on that line with the rays of the angle extending out in both directions from the vertex.