Question

Two circles of radii 5.5 cm and 4.2 cm toch each other extenally. Find the distance between their centres (Explanation)​

Answer 1

Answer:

9.7 cm

Step-by-step explanation:

As they touch externally, Distance between Centres = Sum of radii

                                                                                        = 5.5 + 4.2 = 9.7 cm.

This occurs because if we draw a tangent at the touching point of the circles, then the line joining the tangent and respective centres will be perpendicular to the tangent. And we know that the perpendicular distance between two points is the shortest distance. So, the radii of the two circles will be the shortest distance from the point of contact to the centres. So the directed distance between the centres (i.e., the length of the line joining the centres) = sum of radii.