## MP Board Class 6th Maths Solutions Chapter 5 Understanding Elementary Shapes Ex 5.6

Question 1.

Name the types of following triangles:

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

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

(c) ∆PQR such that PQ = QR – PR = 5 cm.

(d) ∆DEF with m∠D = 90°

(e) ∆XYZ with m∠Y = 90° and XY = YZ.

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

Solution:

(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:

Solution:

(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 the angle by observation)

Solution:

(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) Acute angled triangle and Equilateral 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)

Name the type of triangle in each case.

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

Solution:

(a) Yes, it is possible to make a triangle with 3 matchsticks because sum of lengths of two sides is greater than the length of third side.

(b) No, it is not possible to make a triangle with 4 matchsticks because sum of lengths of two sides is equal to the length of third side.

(c) Yes, it is possible to make a triangle with 5 matchsticks because sum of lengths of two sides is greater than the length of third side.

(d) Yes, it is possible to make a triangle with the help of 6 matchsticks because sum of lengths of two sides is greater than the length of third side.