In the diagram, H and K are the centres of two circles whose radii are 3 cm and 5 cm respectively. The two circles touch each other at C and TN is a common tangent to the circles at A and B. Find the length of AB.
Diagram --> http://img849.imageshack.us/img849/6349/…
Diagram --> http://img849.imageshack.us/img849/6349/…
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HK=3+5=8
BK-AH=5-3=2
AB=√(HK²-(BK-AH)²)=√(8²-2²) =2√15
BK-AH=5-3=2
AB=√(HK²-(BK-AH)²)=√(8²-2²) =2√15