Question

The area of the shaded region is 20 cm². Find the value of x, correct to 3 significant figures

Answer 1

Answer:

Step-by-step explanation:

AC is the diameter of the circle.

In the right angled triangle ADC, we have

AC2=AD2+DC2 (Pythagoras theorem)

AC2=52+122

AC2=25+144

AC2=169

AC=13 cm

Radius of the circle = 2AC=213=6.5 cm

Area of the shaded part = Area of the circle − Area of the rectangle

                                         = πr2−lb

                                         = 3.14×6.52−(5×12)

                                         =132.665−60

                                         =72.665 cm2