Name the types of triangle based on:

(a) Sides

(b) Angles

Give one example each.

(a) On the basis of sides, triangles are of three types :

(i) Scalene triangle — all three sides are of different lengths. Example : sides 3 cm, 4 cm, 5 cm.

(ii) Isosceles triangle — two sides are equal. Example : sides 5 cm, 5 cm, 8 cm.

(iii) Equilateral triangle — all three sides are equal. Example : sides 6 cm, 6 cm, 6 cm.

(b) On the basis of angles, triangles are of three types :

(i) Acute-angled triangle — all angles are less than 90°. Example : 60°, 60°, 60°.

(ii) Right-angled triangle — one angle is exactly 90°. Example : 90°, 45°, 45°.

(iii) Obtuse-angled triangle — one angle is greater than 90°. Example : 120°, 30°, 30°.

Hence, based on sides — Scalene, Isosceles, Equilateral; based on angles — Acute-angled, Right-angled, Obtuse-angled.