Page 164 - Maths Skills - 7

162 Maths

Activity

Objective: To establish the properties relating to different pairs of angles formed by a transversal with
two parallel lines.

Pre-Requisite Knowledge: Concept of lines and line segment.

Materials Required: Sheet of white and coloured papers, scissors, glue,
a geometry box, carbon paper and a pencil/pen

Procedure: 1. Draw two lines l and l parallel to each other and a
2
1
transversal l intersecting them. Label the angles thus Fig. 1
3
obtained by numbers 1 to 8 (Fig. l).
2. Make a cut out of ∠1 on a coloured paper placing it below the figure and marking impressions
by using carbon paper or tracing paper.

3. Place the cut out of the angle on ∠5 and check whether the two angles cover each other or not.
Note that these angles make a pair of corresponding angles.

4. Identify the other pairs of corresponding angles and repeat steps 2 and 3 to check whether the
two angles cover and other or not.
5. Observe the pair ∠4 and ∠5. They make a pair of alternate interior angles. Copy, cut out and
place ∠4 on ∠5 in steps 2 and 3 above.

6. There is one more pair of alternate interior angles. Identify it and check whether the two angles
cover each other by repeating the step 2 and 3.

7. Observe the pair of angles 4 and 6. They make a pair of interior
angles on the same side of the transversal. Copy, cut out and place
them adjacent to each other with one arm of each coinciding. The
other two arms will form a straight line (Fig. 2). Fig. 2