Triangles: CBSE maths class 9.<br />definition and its figures.<br />parts of triangle -<br />vertices, sides and angles.<br />types of triangles on basis of sides-<br />equilateral triangle, isosceles triangle, <br />scalene triangle.<br />types of triangles on basis of angles-<br />right-angled triangle, acute-angled triangle,<br />obtuse-angled triangle.<br />special type- isosceles right-angled triangle.
