What is the part of the circumference of a circle between two points on the circle called?

Define a "sector of a circle" and identify its boundaries.

Write the formula for the arc length of a sector with radius r and angle at the centre θ.

Calculate the arc length of a semi-circle with a diameter of 28 cm.

A sector of a circle has a radius of 21 cm and the angle at its centre is 120∘. What is the length of its arc?

Find the perimeter of a sector of a circle of radius 21 cm and angle at the centre 60∘.

The arc length of a sector is 44 cm and its radius is 21 cm. What is the angle at the centre of this sector?

The perimeter of a semi-circle is 180 cm. Calculate its radius.

A rectangular figure with a length of 20 cm and a breadth of 14 cm has a semi-circle attached to one of its breadths. Calculate the perimeter of the composite figure.

The perimeter of a sector which is 32​ of a circle is 260 cm. Find its radius.

An equilateral triangle of side length 7 cm is drawn within a sector where the radius is equal to the side length of the triangle. Find the perimeter of the region bounded by the arc and the two sides of the triangle which are not radii.

A square lamina has a side length of 15 cm. A quarter-circle of radius 7 cm is cut from one corner (vertex A) and a right-angled triangle with perpendicular sides 8 cm and 6 cm is cut from the adjacent corner (vertex E). Calculate the perimeter of the remaining portion of the lamina.

A pond is shaped like a rectangle of length 35 m and breadth 14 m, with two semi-circles attached to each of its breadths. Find the perimeter of the pond.

A sector of a circle with a radius of 21 cm has an angle at the centre of 120∘. This sector is cut out from a circular lamina. Show that the perimeter of the remaining portion of the lamina is 130 cm.

A grill design is made by combining two identical sectors of a circle inside a rhombus where one of the angles is 60∘ and the side length is 21 cm. Calculate the total length of wire required for the curved parts of the grill.