NCERT Solutions for Class 7th Maths Chapter 5 In-text Questions — Between Lines
Book page 109 Updated on2026-09-19
Q1.
Observe Fig. 5.5 and describe the way the line segments meet or cross each other in each case, with appropriate mathematical words (a point, an endpoint, the midpoint, meet, intersect) and the degree measure of each angle. For example, line segments FG and FH meet at the endpoint F at an angle 115.3°.
Fig. 5.5, page 109 — the pairs of line segments ST and UV, AB and CD, OP and QR, FG and FH, and IJ and LM.
Answer
There are five pairs in Fig. 5.5. Here is a description of each, with the angle you should get on measuring.
Pair
How they meet
Angle
FG and FH
They meet at the endpoint F — F is an end of both segments (given example)
115.3°
AB and CD
They intersect at a point X. X is inside both segments, so it is an endpoint of neither
about 60° (and 120° on the other side)
IJ and LM
They intersect at a point Y, which lies near the middle of each segment
about 79° (and 101° on the other side)
ST and UV
They do not meet at all inside the figure — no common point
no angle formed
OP and QR
They do not meet at all — they stay the same distance apart
no angle formed
Why it happens: The words describe where the meeting happens. If the common point is an end of a segment we say the segments meet at an endpoint; if the common point lies inside both, we say the segments intersect at that point.
Tip: Measure all four angles at X and at Y. You should find two equal pairs each time, and each neighbouring pair adding to 180° — the very properties proved on page 107.
Q2.
Are line segments ST and UV likely to meet if they are extended?
Answer
Yes. They look almost parallel, but they are not — they slowly come closer as you go to the right.
Gap between ST and UV at the left ends ≈ 12 units Gap at the right ends ≈ 9 units The gap is shrinking → the lines are converging
So if both segments are extended far enough towards the right, they will cross.
Why it happens: UV is tilted a little more steeply than ST (about 22° against about 20°). Two lines that are not tilted by exactly the same amount must meet somewhere, however small the difference is — you may just have to extend them a long way.
Tip: Do not trust the eye. Measure the perpendicular gap at two places far apart. If the two gaps differ, the lines are not parallel.
Q3.
Are line segments OP and QR likely to meet if they are extended?
Answer
No. OP and QR are parallel, so they will never meet however far they are extended.
Tilt of OP ≈ 33° below the horizontal Tilt of QR ≈ 33° below the horizontal Same tilt → the perpendicular gap stays the same everywhere
Why it happens: Two lines meet only when they lean differently. OP and QR lean by the same amount, so the space between them never closes up.
Check it yourself: Measure the shortest (perpendicular) distance from O to line QR and from P to line QR. Both give the same value for a parallel pair.