1Fill in the blank: when two lines are parallel, the alternate angles are ......... .
2Fill in the blank: when two lines are parallel, the corresponding angles are ......... .
3Fill in the blank: when two lines are parallel, the sum of the co-interior angles is ......... .
4A transversal EF cuts line AB at G and line CD at H. Write down the pairs of corresponding angles, alternate angles and co-interior angles.
5Two lines are cut by a transversal. Explain how measuring the angles tells you whether or not the two lines are parallel.
6A pair of alternate angles measures 95 degrees and 100 degrees. Are the two lines parallel?
7A point C lies off a given line AB. How do you draw a line CD through C that is parallel to AB?
8An angle of 73 degrees stands on a straight line. Find the other angle made at that point.
9A segment is drawn between two parallel lines making a Z shape, and the angle at one corner is 40 degrees. What is the angle at the other corner?
10At one point the angles \( 2x \) and x together make a straight line. Find the value of x.
11Two lines cross at a point, making \( 2x - 70^\circ \) and x a pair of vertically opposite angles. Find x.
12A transversal cuts two parallel lines making co-interior angles \( 4x \) and \( 5x \). Find the value of x.
13A transversal cuts two parallel lines making co-interior angles \( 2x \) and \( 9x - 40^\circ \). Find x.
14Four straight lines all pass through one single point. Can any one of them be called a transversal? Give the reason.
15AB and CD are parallel. One interior angle is 118 degrees. Write the measures of all eight angles.
16A pair of angles both measure 90 degrees. If the pair could be alternate angles or co-interior angles, are the lines parallel?
17Three lines l, m and n are given. Lines l and m are parallel, and a transversal cutting all three makes a corresponding angle of 65 degrees with l and also 65 degrees with n. What is the relation between m and n?
18A student says that both co-interior angles must be bigger than 90 degrees. Is the statement right or wrong? Give the reason.