These NCERT Solutions for Class 6 Maths Chapter 5 Understanding Elementary Shapes Ex 5.6 Questions and Answers are prepared by our highly skilled subject experts.

## NCERT Solutions for Class 6 Maths Chapter 5 Understanding Elementary Shapes Exercise 5.6

Question 1.

Name the types of following triangles:

(a) Triangle with lengths of sides 7 cm, 8 cm and 9 cm.

(b) ΔABC with AB = 8.7 cm, AC = 7 cm and BC 6 cm.

(c) ΔPQR such that PQ = QR = PR = 5 cm.

(d) ΔDEF with m∠D = 90°

(e) ΔXYZ with m∠Y = 90° and XY – YZ

(f) ΔLMN with m∠L = 30° , m∠M = 70° and m∠N = 80°.

Answer:

(a) Scalene triangle

(b) Scalene triangle

(c) Equilateral triangle

(d) Right-angled triangle

(e) Isosceles right-angled triangle

(f) Acute-angled triangle

Question 2.

Match the following:

Measure of Triangle Types of Triangle

(i) 3 sides of equal length (a) Scalene

(ii) 2 sides of equal length right angled (b) Isosceles

(iii) All sides are of different length angled (c) Obtuse

(iv) 3 acute angles angled (d) Right

(v) 1 right angle (e) Equilateral

(vi) 1 obtuse angle angled (f) Acute

(vii) 1 right angle with two sides of equal length (g) Isosceles

Answer:

(i) → (e)

(ii) → (g)

(iii) → (a)

(iv) → (f)

(v) → (d)

(vi) → (c)

(vii) → (b)

Question 3.

Name each of the following triangles in two different ways: (You may judge the nature of angle by observation)

Answer:

(a) Acute angled triangle and Isosceles triangle

(b) Right-angled triangle and scalene triangle

(c) Obtuse-angled triangle and Isosceles triangle

(d) Right-angled triangle and Isosceles triangle

(e) Equilateral triangle and acute angled triangle

(f) Obtuse-angled triangle and scalene triangle

Question 4.

Try to construct triangles using match sticks. Some are shown here.

Can you make a triangle with:

(a) 3 matchsticks?

(b) 4 matchsticks?

(c) 5 matchsticks?

(d) 6 matchsticks?

(Remember you have to use all the available matchsticks in each case)

If you cannot make a triangle, think of reasons for it.

Answer:

(a) 3 matchsticks: This is an acute angle triangle and it is possible with 3 matchsticks to make a triangle because sum of two sides is greater than third side.

(b) 4 matchsticks: This is a square, hence with four matchsticks we cannot make triangle.

(c) 5 matchsticks: This is an acute angle triangle and it is possible to make triangle with five matchsticks, in this case sum of two sides is greater than third side.

(d) 6 matchsticks: This is an acute angle triangle and it is possible to make a triangle with the help of 6 matchsticks because sum of two sides is greater than third side.