### Understanding Elementary Shapes-Solutions Ex-5.6

**CBSE Class –VI Mathematics**

**NCERT 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) with AB = 8.7 cm, AC = 7 cm and BC = 6 cm.

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

(d)DEF with D =

(e)XYZ with Y = and XY = YZ

(f)LMN with L = M = and N =

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 | (b) Isosceles right angle |

(iii) All sides are of different length | (c) Obtuse angle |

(iv) 3 acute angles | (d) Right angle |

(v) 1 right angle | (e) Equilateral |

(vi) 1 obtuse angle | (f) Acute angle |

(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.