If radii of two circles are 4 cm and 2.8 cm. Draw figure of these circles touching each other – (i) externally (ii) internally

Explanaiton:- 

Given, the radii of the two circles are 4 cm and 2.8 cm.

If two circles touch each other externally, then the distance between their centres is equal to the sum of the radii. In this case, since the circles touch externally, their centres lie on the line passing through the point of contact.

Let the centres of the two circles be denoted by P and Q, and let their point of contact be denoted by R. Since the circles touch externally, the distance between their centres can be calculated as follows:

Distance between the centres = PR + QR

Here, PR is the radius of the larger circle and QR is the radius of the smaller circle.

Substituting the given values, we get:

Distance between the centres = 4 cm + 2.8 cm

= 6.8 cm

Therefore, the distance between the centres of the circles that touch each other externally is 6.8 cm.

If two circles touch each other internally, then the distance between their centres is equal to the difference of the radii. In this case, the centres of the circles lie on the same line, but on opposite sides of the point of contact.

Again, let the centres of the two circles be denoted by P and Q, and let their point of contact be denoted by R. Since the circles touch internally, the distance between their centres can be calculated as follows:

Distance between the centres = PR – QR

Here, PR is the radius of the larger circle and QR is the radius of the smaller circle.

Substituting the given values, we get:

Distance between the centres = 4 cm – 2.8 cm

= 1.2 cm

Therefore, the distance between the centres of the circles that touch each other internally is 1.2 cm.