The length of the direct common tangent to two circles of radii 12 cm and 4 cm is 15 cm. Calculate the distance between their centres.
Circles
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Question

The length of the direct common tangent to two circles of radii 12 cm and 4 cm is 15 cm. Calculate the distance between their centres.

KnowledgeBoat · Accepted Answer

Let there be two circles with center A and B and radius 12 and 4 cm respectively. From figure, TT' is the common tangent. DT = BT' = 4 cm. DB = TT' = 15 cm. In right angled triangle ADB AD = AT - DT = 12 - 4 = 8 cm Hence, the distance between two centres = 17 cm.

Mathematics

The length of the direct common tangent to two circles of radii 12 cm and 4 cm is 15 cm. Calculate the distance between their centres.

Circles

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