Length of an arc

If the length of an arc of a circle of radius a is equal to that of an arc of a circle of radius 2a, then the angle of the corresponding sector of the first circle is double the angle of the corresponding sector of the other circle. Is this statement false? Why?

If the angle of a sector is 45^(@) and the radius of the sector is 28 cm then the length of the arc is _________.

If the angle of a sector is 30^(@) and the radius of the sector is 21 cm, then length of the arc of the sector is ______.

Write the area of the sector of a circle whose radius is r and length of the arc is l .

In a circle of radius 42 cm, an arc subtends an angel of 72° at the centre. What is the length of the arc?

In a circle of radius 4 cm, an arc subtends an angle of 60^(@) at the centre. Find the length of the arc.

In a circle of radius r cm, an arc subtends an angle of 60^(@) at the centre. The length of the arc will be :