Question

Given below is the result of an annual examination of a class, showing the percentage of students in each category.

$\begin{array}{cccc}\text{First division}& \text{Second division}& \text{Third division}& \text{Failed}\\ 25\%& 45\%& 20\%& 10\%\end{array}$

$\text{Represent the above data by a pie chart.}$

Answer 1

$\text{Total percentage = 25 + 45 + 20 + 10 =}100\%$

$\begin{array}{ccc}\text{Division}& \text{Percentage}& \text{Central angle}\\ \text{First division}& 25\%& \frac{25}{100}\times {360}^{\circ }={90}^{\circ }\\ \text{Second division}& 45\%& \frac{45}{100}\times {360}^{\circ }={162}^{\circ }\\ \text{Third division}& 20\%& \frac{20}{100}\times {360}^{\circ }={72}^{\circ }\\ \text{Failed}& 10\%& \frac{10}{100}\times {360}^{\circ }={36}^{\circ }\\ \text{Total}& 100\%& {360}^{\circ }\end{array}$

$\text{(i) Draw a circle with a suitable radius.}\text{(ii) Draw a horizontal radius.}\text{(iii) Starting from this radius, draw sectors of central angles}{90}^{\circ },{162}^{\circ },{72}^{\circ },and{36}^{\circ }\text{respectively.}\text{(iv) Shade these sectors with different colours or designs as shown in the figure.}$