If all angles of a triangle are less than a right angle, then it is called ______________.

If two sides of a triangle are 5 cm and 9 cm, then the third side is ______________

The angles of a right angled triangle are

An equilateral triangle is

Which of the following can be the sides of an isosceles triangle?

Classify the given triangles based on its angles as acute angled, right angled or obtuse angled.

Classify the following triangles based on its sides and angles.

If one angle of an isosceles triangle is 124°, then find the other angles.

Is a triangle possible with the angles 90°, 90° and 0°? Why?

If one angle of an isosceles triangle is 70°, then find the possibilities for the other two angles.

Can a triangle be formed with 7 cm, 10 cm and 5 cm as its sides?

Can a triangle be formed with 8 cm, 3 cm and 4 cm as its sides?

Can a triangle be formed with the angles 80°, 30°, 40°?

Draw a line segment measuring 7.8 cm. Mark a point B above it at a distance of 5 cm. Through B draw a line parallel to the given line segment.

Draw a line and mark a point R below it at a distance of 5.4 cm Through R draw a line parallel to the given line.

Can a triangle be formed with the following angles? If yes, name the type of triangle.
(i) 60°, 60°, 60° 
(ii) 90°, 55°, 35° 
(iii) 60°, 40°, 42°
(iv) 60°, 90°, 90°
(v) 70°, 60°, 50°
(vi) 100°, 50°, 30°

Two angles of the triangles are given. Find the third angle.
(i) 80°, 60° 
(ii) 75°, 35°
(iii) 52°, 68°
(iv) 50°, 90°
(v) 120°, 30° 
(vi) 55°, 85°

Draw a line and mark a point R at a distance of 4.8 cm above the line. Through R draw a line parallel to the given line.

Draw a line segment PQ = 12 cm. Mark two points M, N at a distance of 5 cm above the line segment PQ. Through M and N draw a line parallel to PQ.