# Angles and Pairs of Angles

Corners and angle pairs

Parallel lines are when they are always at the same distance from each other (called "equidistant") and never meet. If two parallel lines are specified in a figure, there are two main areas: the inner and the outer. In addition, two intersecting lines form pairs of congruent angles called vertical angles. We' ve got names for angle pairs, too. Corners are formed when lines intersect.

## Interactive: angle

Tonight we're gonna study angles. Sophomore: Student: What's an elbow? I know what an elbow is! Sophomore: Student: There are three types of angles: pointed, blunt and right. Let us first know what a right corner is. Righteous angles are present in many places in reality. Right angles are angles measuring 90ยบ.

Right angles look like this: And the second kind of angles are sharp. A sharp corner is an corner whose dimension lies between 0 and 90 degree. A sharp corner looks like this: Sophomore: Student: A third kind is an angular dimension of more than 90 degree. Yes, an blunt corner is an corner between 90 and 180 degree.

A blunt corner looks like this: We' ve got a name for a pair of angles, too. Corners are created when intersecting line. Let us look at the angles that form when two straight parallels are cut by a third line, a so-called shear. Here the rudd line is running side-by-side and the blu line is the transverse.

Sophomore: Student: Eight angles were drawn between these strokes. Well, who can show me an ogival corner? Sophomore: Student: Well, who can show me an blunt corner? Pupil 2: I think it's the top one on the upper right. What we need is an easy way to relate to the angles we're speaking of. From now on, we'll be labeling our angles.

The angles a and l are neighboring angles. The angles f and hr are also neighbouring angles. Anybody know what it means when there's a couple of angles next to each other? Sophomore: Student: Yes, neighboring angles are angles that divide a beam. Somebody tell me another set of angles next to each other.

Sophomore: Student: Yes, the angles a and d are side by side. Pupil 2: I can do it too; the angles d and d are next to each other. Nice work, the angles a and d are side by side and the angles a and d as well. There are many pairs of neighboring angles in the image. Well, let's discuss the angles vertically.

The angles a and the angle da are perpendicular angles. The angles f and grams are also perpendicular angles. Could anyone tell what it means when a couple of angles are upright? Sophomore: Student: Were perpendicular angles those that are opposite each other? Upright angles divide only one point. Could anyone name another couple of angles?

Pupil 2: I can; the angles bis and cla are perpendicular angles. Sophomore: Student: The angles f and g are also perpendicular angles. Yes, the angles bis and cla are perpendicular angles and so are the angles cla and cla. Now that we know what neighboring and perpendicular angles are, let's discuss alternative inner angles.

The angles f and f are alternating inner angles. The angles d and e are also alternating inner angles. If two angles are alternately inner angles, who knows what it means? Sophomore: Student: Aren't alternating inner angles the ones that differ within the line and on opposite sides? Yes, alternative inner angles are angles located within the line of parallels and on opposite sides of the shear.

Well, who thinks he can figure out what alternative outer angles are? Sophomore: Student: These are the angles on the outer sides of the line and on the opposite sides of the shear. Sophomore: Student: The angles a and a are alternative outer angles. Students 2: The angles c and d are also alternative outer angles.