Maths 2 Mark Question

Place the ruler so that one of its measuring edges lies along the line l. Hold it firmly with one hand. Now place a set square with one arm of the right angle coinciding with the edge of the ruler. Draw line segments between l and m (say PM, RS, AB) with the set square. Now, we see that PM = AB = RS. Thus, we can say that l || m.

Line segments AB and CD will intersect if they are produced endlessly towards the ends A and C, respectively.
Therefore, they are not parallel to each other.

At point A, AB is the perpendicular distance between l and m.
At point C, CD is the perpendicular distance between l and m.
The perpendicular distance between two parallel lines is same at all points.
Therefore, CD = AB = 2.3cm

Following are the parallel edges of the top:
AD || BC
This is because AD and BC will not intersect even of both these line segments are produced to infinity in both the directions.
AB || DC
This is because AB and DC will not intersect even if both these line segments are produced to infinity in both the directions.

In this case, we see that when we draw line segments between l and m, they are unequal, i.e., PM neq RS. Therefore, l is not parallel to m.

The groups of parallel edges are (AD || GH || BC || FE), (AB || DC || GF || HE) and (AH || BE || CF || DG).
The above mentioned groups of edges are parallel because they will not meet each other if produced to infinity to both sides.