## Classify Triangles - Questions

Practice Page 1

 Q1. Classify the triangles into acute, obtuse and right angled triangle with following angles: a.   30°, 90°, 60°                       _________________________ b.   55°, 45°, 80°                       _________________________ c.   80°, 60°, 40°                       _________________________ d.   120°, 40°, 20°                     _________________________ e.   90°, 45°, 45°                       _________________________ f.    35°, 95°, 50°                       _________________________ Q2. Classify triangles according to sides as equilateral, isosceles or scalene triangle. a. 5cm, 3cm, 6cm                    _________________________   b. 7cm, 7cm, 7cm                    _________________________   c. 8cm, 8cm, 7cm                     _________________________   d. 9cm, 11cm, 10cm                 _________________________   e. 4cm, 5cm, 6cm                     _________________________   f. 4.5cm, 4.5cm, 5.5cm               _________________________ Q3. If two angles of a triangle measures 50° and 60°. Find the measure of the third angle of the triangle.

Practice Page 2

 Q1. Can we have a triangle with the following angles and sides? Justify your answer with reason. a.     50°, 90°, 60°            ______________________ ________________________________________ b.   80°, 70°, 80°            _______________________ _________________________________________        c.     8cm, 4cm, 4cm          _______________________                   __________________________________________ d.    10cm, 5cm, 5cm         ________________________            __________________________________________ Q2. Find the third angle and mention the kind of triangle. a. ∠A = 80°, ∠B = 40°, ∠C =?      _____________________________________________________   b. ∠A = 60°, ∠B = 90°, ∠C =?      _____________________________________________________   c. ∠A = 120°, ∠B = 35°, ∠C =?      _____________________________________________________ Q3. The three angles of a triangle are in the ratio of 2:3:5. Find the measure of each angle of the triangle.

Practice Page 3

 Q1. Draw 3 non collinear points as L, M and N on a paper. Now join LM, MN and NL. Name the figure you get and answer the following question: a.   Name :  ___________________ b.     The side opposite to  ∠M   __________________ c. The angle opposite to side LM   __________________        d.   Vertex opposite to side NM   _________________             e.   The side opposite to angle M  __________________ Q2. Fill in the blanks: a. The sum of 3 angles of a triangle equals to ____________.   b. The sum of the lengths of any two sides of a triangle is ______________ than the length of the third side.   c. In an isosceles triangle, the angles opposite to the equal sides are ____________.   d. An equilateral triangle is also an ______________________ triangle.   e. Triangles are classified on the basis of __________ and on the basis of _________. Q3. If one of the acute angle of a right angled triangle is 42°. Find out the other acute angle of the triangle.