Question 10
In the figure below, PSR, RTQ and PAQ are three semicircles of diameters 10 cm, 3 cm and 7 cm respectively. Find the area of the shaded region.
**Editorial note for this self-study exercise:** Keep the area exact: write it as $c\pi$ cm² and enter only the coefficient c, using a number or a fraction a/b. Use a decimal point if entering a decimal. Do not replace pi by a decimal approximation.
**Editorial note for this self-study exercise:** Keep the area exact: write it as $c\pi$ cm² and enter only the coefficient c, using a number or a fraction a/b. Use a decimal point if entering a decimal. Do not replace pi by a decimal approximation.