Page 7 - Mathematics Class - IX

4.2. To verify experimentally the different criteria for congruency of triangles using triangle cut-outs. 43
4.3. To verify experimentally that in a triangle, the longer side has the greater angle opposite to it. 48

4.4. To verify that – 51

(a) Area of a parallelograms on the same base and between the same parallels are equal.
(b) Area of triangles on the same base and between the same parallels are equal.
4.5. To verify that the ratio of the areas of a parallelogram and a triangle on the same base and between 55
the same parallels is 2:1.

4.6. To verify that “The angle subtended by the arc at the centre of the circle is double the angle subtended 58
by it at any other point on the circumference of the circle.”

4.7. To verify that in a circle, angles in the same segments are equal. 62
4.8. To verify that the opposite angles of a cyclic quadrilateral are supplementary. 65

UNIT - 5: Mensuration

5.1. To form a cone from a sector of a circle and to find the formula for its curved surface area. 70

5.2. To find a formula for the curved surface area of a right-circular cylinder, experimentally. 73
5.3. To obtain the formula for the surface area of a sphere. 76

5.4. To find the relationship among the volumes of a right-circular cone, a hemisphere and a right 79

circular cylinder of equal radii and equal heights.

UNIT - 6: Statistics

6.1. To draw histograms for classes of equal width and varying widths. 83

PROJECTS

1. Story of p . 89
2. Chronology of Indian Mathematicians with their contributions. 90

3. To develop Heron’s formula for area of a triangle. 91
4. Development of formula for the area of a cyclic quadrilateral. 92

5. Generation of Pythagorean triplets. 94
6. Magic Squares. 96

7. With rectangle of given perimeter, finding the one with a maximum area and with rectangle of 97
given area, finding the one with least perimeter.

GLOSSARY