Page 53 - Mathematics Class - IX

ACTIVITY 4.4

OBJECTIVE

To verify that:
(a) Area of 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.

MATERIALS REQUIRED

Glazed paper Adhesive
A pair of scissors Geometry box

PRE-REQUISITE KNOWLEDGE
1. Area of a parallelogram

2. Area of a triangle
3. Concept of perpendicular between two parallels

THEORY

1. Parallelogram: A quadrilateral in which both pairs of opposite sides are parallel. A B

2. Area of a parallelogram: Base × Height

1 Height
3. Area of a triangle: × Base × Height
2
D C
Base
PROCEDURE

(a) 1. Draw and cut a parallelogram ABCD as shown in Fig. (a (i)).

2. Mark a point P on DC as shown in Fig. (a (ii)).

D C D P C

A B A B
X

Fig. (a (i)) Fig. (a (ii))

3. From A, make a crease along AP and fold it. Join it with dotted line as shown in Fig. (a (ii)).

51