List of top Mathematics Questions on Classification of Triangles

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°.

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. 

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

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