Kerala Board Solutions for Chapter: Circle Measures, Exercise 5: Exercise 5

In a circle, the length of an arc of central angle $40°$ is $3\pi$ centimetres. What is the perimeter of the circle? What is its radius?

In a circle, the length of an arc of central angle $25°$ is $4$ centimetres. In the same circle, what is the length of an arc of central angle
$75°?$ Write the answer in centimetres.

In a circle, the length of an arc of central angle $25°$ is 4 centimetres. In a circle of radius one and a half times the radius of this circle, what is the length of an arc of central angle $75°?$ Write the answer in centimetres.

From a bangle of radius $3$ centimetres, a piece is to be cut out to make a ring of radius $\frac{1}{2}$ centimetres. What should be the central angle of the piece to be cut out? Write the answer in number of degrees $\left(°\right)$.

From a bangle of radius $3$ centimetres, a piece is to be cut out to make a ring of radius $\frac{1}{2}$ centimetres. The remaining part of the bangle was bent to make a smaller bangle. What is its radius? Write the answer in centimetres.

The picture shows the parts of a circle centered at each vertex of an equilateral triangle and passing through the other two vertices. What is the perimeter of this figure? Write the answer in centimetres.

Parts of circles are drawn, centered at each vertex of a regular octagon and a figure is cut out as shown below:

Calculate the perimeter of the figure. Write the answer without unit and up to $2$ decimal places. Take $\mathrm{\pi }=3.14$