The diagram shows a sector ABC of a circle with centre A and radius 8 cm. The area of the sector is \(\frac{16}{3} \pi \text{ cm}^2\). The point D lies on the arc BC.
Find the perimeter of the segment BCD.
The diagram shows part of a circle with centre O and radius 6 cm. The chord AB is such that angle AOB = 2.2 radians. Calculate:
(i) the perimeter of the shaded region,
(ii) the ratio of the area of the shaded region to the area of the triangle AOB, giving your answer in the form k : 1.
The diagram shows sector OAB with centre O and radius 11 cm. Angle AOB = \(\alpha\) radians. Points C and D lie on OA and OB respectively. Arc CD has centre O and radius 5 cm.
(i) The area of the shaded region ABDC is equal to \(k\) times the area of the unshaded region OCD. Find \(k\).
(ii) The perimeter of the shaded region ABDC is equal to twice the perimeter of the unshaded region OCD. Find the exact value of \(\alpha\).
The diagram shows points A, C, B, P on the circumference of a circle with centre O and radius 3 cm. Angle AOC = angle BOC = 2.3 radians.
(i) Find angle AOB in radians, correct to 4 significant figures.
(ii) Find the area of the shaded region ACBP, correct to 3 significant figures.
In the diagram, OAB and OCD are radii of a circle, centre O and radius 16 cm. Angle AOC = \(\alpha\) radians. AC and BD are arcs of circles, centre O and radii 10 cm and 16 cm respectively.
(i) In the case where \(\alpha = 0.8\), find the area of the shaded region.
(ii) Find the value of \(\alpha\) for which the perimeter of the shaded region is 28.9 cm.