9. The area of a rectangle is found by multiplying the length by the width. For the following rectangles fi nd the area in terms of a and b .
3a
Length Width 4a
6ab 10ab 8ab 12ab
10. The area of a triangle is found by multiplying half the base by the perpendicular height. For the following triangles, fi nd the area in terms of a and b .
4a
Base Perpendicular height 4a
12ab ab
4·6ab2 a
11. An egg carton is rectangular and is 7y cm long on one side and 6x cm along its width, as shown below.
b2 ) )
Section A Introducing concepts and building skills