Value of Pi

Q.

The length of the minute hand of a clock is 5 cm. Find the area swept by the minute hand during the time period 6: 05 am and 6: 40 am.

1. $35\frac{7}{9}c{m}^2$

2. $45\frac{3}{8}c{m}^2$

3. $45\frac{5}{6}c{m}^2$

4. $25\frac{5}{6}c{m}^2$

Q. Question 45

Fill in the blanks to make the statement true.

Ratio of the circumference of a circle to its diameter is denoted by symbol ___.

Q.

Find the area of the shaded region in Fig, if PQ = 24 cm, PR = 7 cm and O is the centre of the circle.

1. $140c{m}^2$

2. $151.5c{m}^2$

3. $161.5c{m}^2$

4. $155.5c{m}^2$

Q.

A circum-circle is drawn around a right triangle PQR. The height and the base of the triangle are 5 cm and 12 cm, respectively. What would be the area of the shaded region?

1. 100 $c{m}^2$

2. 95 $c{m}^2$

3. 96.33 $c{m}^2$

4. 102.6 $c{m}^2$

Q. A traffic signal board, indicating ${}^{\prime }SCHOOLAHEA{D}^{\prime }$, is an equivalent triangle with side '$a$'. Find the area of the signal board, using Heron's formula. If its perimeter is $180cm$, what will be the area of the signal board?

Q.

An umbrella has 8 ribs which are equally spaced. Assuming the umbrella to be a flat circle of radius 45 cm, find the area between two consecutive ribs of the umbrella.

1. $769c{m}^2$

2. $794.8c{m}^2$

3. $700c{m}^2$

4. $798.6c{m}^2$

Q.

$2<3<\pi <5$ [Say true or false]

1. True

2. False

Q. π is the ratio of circumference of a circle to its diameter.

1. True
2. False

Q. In $\Delta ABC,AB=76$ cm, $BC=69$ cm and $CA=61$ cm

1. $\angle C$
2. $\angle A$
3. $\angle B$
4. All are equal

Q. π is the ratio of circumference of a circle to its __________.

1. radius
2. area
3. radius²
4. diameter

Q.

Which of the following number gives a more accurate value of π?

1. 22/7

2. 355/113

3. 157/50

4. 16/5

Q.

If the ratio of circumference of two circles is 5:7, then find the ratio of its diameters.

Q. If we divide the circumference of any circle with it's diameter, we always get a variable value.

1. True
2. False