To start, draw two parallel lines. One that follows an ... of interior angles in a triangle by 3 In an isosceles triangle, two of the sides are equal. This means two of the angles are equal.

If the triangles are congruent and each ... with the other angle mirroring the opposite side. This example occurs when two parallel lines are intersected by a third straight line.

Show that BC || QR. 7. Using Theorem 6.1, prove that a line drawn through the mid-point of one side of a triangle parallel to ...