Kala - Co-interior Angles on Parallel Lines

In this section, we will investigate one final pair of angles formed when two parallel lines are intersected by another line (known as a transversal). [br][br]The applet below shows examples of [i]co-interior angles:[/i]

Use the applet above to investigate co-interior angles. [br]In your own words, describe what [i]co-interior[/i] angles are.

What do co-interior angles add up to?

[math]150^\circ[/math] [math]90^\circ[/math] [math]180^\circ[/math] [math]0^\circ[/math]

PART 1

For each diagram below, decide whether the angles marked are co-interior angles or not.

Which of the above diagrams show co-interior angles?

d a b c

PART 2

Consider the diagram below:

What is the size of the other marked angle?

[math]66^\circ[/math] [math]180^\circ[/math] [math]104^\circ[/math] [math]76^\circ[/math]

Information: Kala - Co-interior Angles on Parallel Lines