Question Detail
Question
To construct a tangential curve of radius R externally to two circles of radii r1 and r2 (as depicted on page 20), what radii are used for the arcs drawn from the centers A and B of the two given circles to find the center (O) of the tangential curve?
Correct Answer
Option B is the correct answer.
Detailed Explanation
Page 20, steps 2 and 3, state: 'With centre A and radius R+r1, draw an arc' and 'With centre B and radius R+r2, draw an arc to intersect the first arc at O.' This addition of radii is characteristic for external tangency to two circles.
Hint
Refer to 'To Construct a Curve Tangential to Two Circles' (external tangency) on page 20, noting steps 2 and 3 and the labels on the diagram.