(i)[3]
Show that $CBY = 1.445$ radians, correct to $4$ significant figures.
(ii)[4]
Determine the perimeter of the shaded region.
Mathematics 9709 · AS & A Level · Circular measure
Circular measure — practice question
The diagram depicts an isosceles triangle $ACB$ with $AB = BC = 8\text{ cm}$ and $AC = 12\text{ cm}$. Arc $XC$ is taken from a circle centred at $A$ with radius $12\text{ cm}$, while arc $YC$ comes from a circle centred at $B$ with radius $8\text{ cm}$. Points $A$, $B$, $X$ and $Y$ all lie on one straight line.