Mathematics Solutions Solutions for Class 6 Maths Chapter 15 Triangles And Their Properties are provided here with simple step-by-step explanations. These solutions for Triangles And Their Properties are extremely popular among Class 6 students for Maths Triangles And Their Properties Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Mathematics Solutions Book of Class 6 Maths Chapter 15 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Mathematics Solutions Solutions. All Mathematics Solutions Solutions for class Class 6 Maths are prepared by experts and are 100% accurate.

Page No 80:

Question 1:

Observe the figures below and write the type of the triangle based on its angles.

 

Answer:

In △PQR, ∠Q = 90∘ (a right angle)
Therefore, △PQR is a right angle traingle.
In △XYZ, ∠Y = 125∘ (an obtuse angle)
Therefore, ​△XYZ is an obtuse angle traingle.
In △LMN, all angles are acute angles.
Therefore, ​△LMN is a acute angle traingle.

Page No 80:

Question 2:

Observe the figures below and write the type of the triangle based on its sides.

Answer:

In △ABC, all sides are equal.
Therefore, △ABC is an equilateral traingle.
In △DEF, all sides are different.
Therefore, ​△DEF is a scalene traingle.
In △UVQ, two sides are equal.
Therefore, ​△UVW is an isosceles traingle.

Page No 80:

Question 3:



As shown in the figure, Avinash is standing near his house. He can choose from two roads to go to school. Which way is
shorter? Explain why.

Answer:

In any triangle, the sum of the lengths of any two sides of a triangle is always greater than the third side.
Therefore, in △ABC, AC < AB + BC.
Hence, the shortest way to reach school is via AC.

Page No 80:

Question 4:

The lengths of the sides of some triangles are given. Say what types of triangles they are.
(1) 3 cm, 4 cm, 5 cm                       (2) 3.4 cm, 3.4 cm, 5 cm
(3) 4.3 cm, 4.3 cm, 4.3 cm              (4) 3.7 cm, 3.4 cm, 4 cm

Answer:

(1)
All sides are different.
Therefore, ​it is a scalene traingle.
(2)
Two sides are equal.
Therefore, ​it is an isosceles traingle.
(3)
​All sides are equal.
Therefore, it is an equilateral traingle.
(4)
All sides are different.
Therefore, ​it is a scalene traingle.
 

Page No 80:

Question 5:

The lengths of three segments are given for constructing a triangle. Say whether a triangle with these sides can be drawn. Give the reason for your answer.
(1) 17 cm, 7 cm, 8 cm           (2) 7 cm, 24 cm, 25 cm
(3) 9 cm, 6 cm, 16 cm           (4) 8.4 cm, 16.4 cm, 4.9 cm
(5) 15 cm, 20 cm, 25 cm       (6) 12 cm, 12 cm, 16 cm

Answer:

(1) 17 cm, 7 cm, 8 cm       
Here, 17 > 7 + 8 or 17 > 15
In any triangle, the sum of the lengths of any two sides of a triangle is always greater than the third side.
Therefore, the traingle is not possible.    
(2) 7 cm, 24 cm, 25 cm
Here, 7 < 24 + 25 or 7 < 49
24 < 7 + 25 or 24 < 32
25 < 7 + 24 or 25 < 31
In any triangle, the sum of the lengths of any two sides of a triangle is always greater than the third side.
Therefore, the traingle is possible.    
(3) 9 cm, 6 cm, 16 cm 
Here, 16 > 9 + 6 or 16 > 15
In any triangle, the sum of the lengths of any two sides of a triangle is always greater than the third side.
Therefore, the traingle is not possible.           
(4) 8.4 cm, 16.4 cm, 4.9 cm
Here, 16.4 > 8.4 + 4.9 or 16.4 > 13.3
In any triangle, the sum of the lengths of any two sides of a triangle is always greater than the third side.
Therefore, the traingle is not possible.        
(5) 15 cm, 20 cm, 25 cm 
Here, 15 < 20 + 25 or 15 < 45
20 < 15 + 25 or 20 < 40
25 < 15 + 20 or 25 < 35
In any triangle, the sum of the lengths of any two sides of a triangle is always greater than the third side.
Therefore, the traingle is possible.         
(6) 12 cm, 12 cm, 16 cm
Here, 12 < 12 + 16 or 12 < 28
12 < 12 + 16 or 12 < 28
16 < 12 + 12 or 16 < 24
In any triangle, the sum of the lengths of any two sides of a triangle is always greater than the third side.
Therefore, the traingle is possible.    



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