A circle is drawn with the hypotenuse of a right triangle as its diameter. If the other two sides of the triangle are 21 cm and 28 cm, what is the area of the circle? (Take \(\pi=\frac{22}{7}\))
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 962.5 cm2
The hypotenuse is found by Pythagoras; it is the diameter, so the radius is half of it, and the area is \(\pi r^2\).
Hypotenuse \(=\sqrt{21^2+28^2}=\sqrt{441+784}=\sqrt{1225}=35\) cm
Radius \(=35\div2=17.5\) cm
Area \(\displaystyle=\frac{22}{7}\times17.5\times17.5=55\times17.5=962.5\) cm2
