Worked examples
Two examples
Example 1
A line crosses two parallel lines. One of the sharp angles is 65°. What is another sharp angle at the other crossing?
- The crossing line makes the same four angles at both parallel lines.
- All the sharp angles are equal.
Answer: 65°
Example 2
Same figure. What is one of the wide angles?
- A sharp angle and a wide angle next to each other make a straight line: 180 − 65.
Answer: 115°
Where this is taught: Quiz 36: Angles, “Two parallel lines, crossed by a third”
The drill
Ten problems
How many:
Type each answer, then press Check my answers at the bottom. Commas in large numbers are fine.Write each answer on the line. The answer key, with the reasoning, is on the last page.