Question

(1) with side 11 cm, (2) with side 9 cm, (3) with side 7 cm and (4) with
side 5cm.
The area of the total dotted region - Area of the lined region is equal
to ....
2
A) 56 cm
B) 64 cm?
C) 78 cm2
D) 89 cm2​

Answer 1

1. Triangles as parts of rectangles2. Generalising for other congruent parts of rectanglesBefore moving onto exercise 11.2, the topics Area of triangle and parallelogram are discussed. Area of a square = side × sideArea of a rectangle = length × breadthArea of a parallelogram = base × heightArea of a triangle =1/2 × base × height In the other half of the chapter, circles are explained. The topic is explained in two parts:1. Circumference of CircleThe distance around a circular region is known as its circumference. Circumference of a circle = πd2. Area of circleArea of circle is given by πr2