Question

The following table shows the percentages of buyers of four different brands of bathing soaps.

Brand	A	B	C	D
Percentage of buyers	20%	40%	25%	15%

Represent the above data by a pie chart.

Answer 1

$$\begin{gathered} \mathrm{Total}\mathrm{percentage}=100 \\ \mathrm{Central}\mathrm{angle}\mathrm{of}\mathrm{each}\mathrm{brand}=\left(\frac{\mathrm{value}\left(\mathrm{in}\%\right)\mathrm{of}\mathrm{each}\mathrm{brand}}{100}\times 360\right)° \\ \mathbf{Calculation}\mathbf{}\mathbf{of}\mathbf{}\mathbf{central}\mathbf{}\mathbf{angles}\mathbf{:} \end{gathered}$$

Brand	Buyers (in %)	Central angle
A	20	$72°$
B	40	$144°$
C	25	$90°$
D	15	$54°$

$$\begin{gathered} \mathbf{Construction}\mathbf{}\mathbf{of}\mathbf{}\mathbf{pie}\mathbf{}\mathbf{chart} \\ \mathrm{Steps}\mathrm{of}\mathrm{construction}: \\ 1.\mathrm{Draw}\mathrm{a}\mathrm{circle}\mathrm{of}\mathrm{any}\mathrm{convenient}\mathrm{radius}. \\ 2.\mathrm{Draw}\mathrm{a}\mathrm{horizontal}\mathrm{radius}\mathrm{of}\mathrm{th}e\mathrm{circle}. \\ 3.\mathrm{Draw}\mathrm{sectors}\mathrm{whose}\mathrm{central}\mathrm{angles}\mathrm{are}72°,144°,90°\mathrm{and}54°. \\ 4.\mathrm{Shade}\mathrm{the}\mathrm{sectors}\mathrm{so}\mathrm{obtained}\mathrm{differently}\mathrm{and}\mathrm{label}\mathrm{each}\mathrm{one}\mathrm{of}\mathrm{them}. \\ \mathrm{Thus},\mathrm{we}\mathrm{obtain}\mathrm{the}\mathrm{required}\mathrm{pie}\mathrm{chart}\mathrm{as}\mathrm{shown}\mathrm{in}\mathrm{the}\mathrm{figure}\mathrm{below}. \end{gathered}$$