Section 1.2

Given:

'parallel lines and angles'

An example of alternate interior angles would \(E\) and \(D\). This also means that \(E=D\).

An example of alternate exterior angles would be \(A\) and \(H\). This means \(A=H\).

From the image above would should know that \(D+F=180^{\circ}\). Further, \(F=B\).

The sum of the measures of the angles of any triangle is \(180^{\circ}\).

Definition 1.4. The following triangles are named from left to right: Equilateral, Isosceles, and Scalene.

'a picture of Equilateral, Isosceles, and Scalene triangles

\(\triangle ABC\) is similar to \(\triangle DEF\) if the following conditions hold true:

  1. Corresponding angles have the same measure.

  2. Corresponding sides are proportional.