In the figure below, BCDE and CDXW are squares. A and Y are centres of square WXDC and BCDE respectively. Z is the centre of CD. If BW = 56 cm, take π as
227 and find
- the perimeter of the shaded region,
- the area of the shaded region.
(a)
Circumference of big circle
=
227 x 28
= 88 cm
Circuference of four small semicircles
= 4 x
12 x
227 x 14
= 88 cm
Circumference of two quadrants
=
14 x 2 x
227 x 28
= 44 cm
Perimeter of the shaded region
= 88 + 88 + 44
= 220 cm
(b)
Area of big circle
=
227 x 14 x 14
= 616 cm
2Area of two shaded quadrant
=
12 x
227 x 14 x 14
= 308 cm
2 Area of shaded region
= 616 + 308
= 924 cm
2 Answer(s): (a) 220 cm; (b) 924 cm
2