Question

Semicircle arc AB,AC,BD and CD divide the circle above in to regions. The points shown along the diameter AD divided in to 6 equal parts. If AD=6 what is the total area of the shaded region?

Answer 1

Area semicircle = π * $r^{2} / 2;$

 the total area of the shaded region = 2 * [ π* ( $BD / 2)^{2}$ / 2 - π* ( $CD / 2)^{2}$ / 2 ] = 4π - 1π = 3π.