**NCERT Solutions For Class 6 Maths Chapter 5 Understanding Elementary Shapes Exercise 5.1** contains problems which help students understand the steps to be followed for measuring line segments by observation, tracing, ruler or divider. The students gain a better hold on the concepts by referring to the solutions created by the faculties at BYJUâ€™S. To understand the concept of measuring line segments, students can access NCERT Solutions Class 6 Maths Exercise 5.1.

## NCERT Solutions for Class 6 Chapter 5: Understanding Elementary Shapes Exercise 5.1 Download PDF

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### Access NCERT Solutions for Class 6 Chapter 5: Understanding Elementary Shapes Exercise 5.1

**1. What is the disadvantage in comparing line segments by mere observation?**

**Solutions:**

By mere observation we canâ€™t compare the line segments with slight difference in their length. We canâ€™t say which line segment is of greater length. Hence, the chances of errors due to improper viewing are more.

**2. Why is it better to use a divider than a ruler, while measuring the length of a line segment?**

**Solutions:**

While using a ruler, chances of error occur due to thickness of the ruler and angular viewing. Hence, using divider accurate measurement is possible.

**3. Draw any line segment, say . Take any point C lying in between A and B. Measure the lengths of AB, BC and AC. Is AB = AC + CB?**

**Solutions:**

Since given that point C lie in between A and B. Hence, all points are lying on same line segment

. Therefore for every situation in which point C is lying in between A and B we may say that

AB = AC + CB

For example:

AB is a line segment of length 7 cm and C is a point between A and B such that AC = 3 cm and CB = 4 cm.

Hence, AC + CB = 7 cm

Since, AB = 7 cm

âˆ´ AB = AC + CB is verified.

**4. If A, B, C are three points on a line such that AB = 5 cm, BC = 3 cm and AC = 8 cm, which one of them lies between the other two?**

**Solutions:**

Given AB = 5 cm

BC = 3 cm

AC = 8 cm

Now, it is clear that AC = AB + BC

Hence, point B lies between A and C.

**5. Verify, whether D is the mid point of .**

**Solutions:**

Since, it is clear from the figure that AD = DG = 3 units. Hence, D is the midpoint of** **

**6. If B is the mid point of and C is the mid point of , where A, B, C, D lie on a straight line, say why AB = CD?**

**Solutions:**

Given

B is the midpoint of AC. Hence, AB = BC (1)

C is the midpoint of BD. Hence, BC = CD (2)

From (1) and (2)

AB = CD is verified

**7. Draw five triangles and measure their sides. Check in each case, if the sum of the lengths of any two sides is always less than the third side.**

**Solutions:**

Case 1. In triangle ABC

AB= 2.5 cm

BC = 4.8 cm and

AC = 5.2 cm

AB + BC = 2.5 cm + 4.8 cm

= 7.3 cm

As 7.3 > 5.2

âˆ´ AB + BC > AC

Hence, the sum of any two sides of a triangle is greater than the third side.

Case 2. In triangle PQR

PQ = 2 cm

QR = 2.5 cm

PR = 3.5 cm

PQ + QR = 2 cm + 2.5 cm

= 4.5 cm

As 4.5 > 3.5

âˆ´ PQ + QR > PR

Hence, the sum of any two sides of a triangle is greater than the third side.

Case 3. In triangle XYZ

XY = 5 cm

YZ = 3 cm

ZX = 6.8 cm

XY + YZ = 5 cm + 3 cm

= 8 cm

As 8 > 6.8

âˆ´ XY + YZ > ZX

Hence, the sum of any two sides of a triangle is greater than the third side.

Case 4. In triangle MNS

MN = 2.7 cm

NS = 4 cm

MS = 4.7 cm

MN + NS = 2.7 cm + 4 cm

6.7 cm

As 6.7 > 4.7

âˆ´ MN + NS > MS

Hence, the sum of any two sides of a triangle is greater than the third side.

Case 5. In triangle KLM

KL = 3.5 cm

LM = 3.5 cm

KM = 3.5 cm

KL + LM = 3.5 cm + 3.5 cm

= 7 cm

As 7 cm > 3.5 cm

âˆ´ KL + LM > KM

Hence, the sum of any two sides of a triangle is greater than the third side.

Therefore we conclude that the sum of any two sides of a triangle is always greater than the third side.