GEOMETRY XI

Looking at only the left circle:  MB · MA  =  MT · MT

--->                                             3  ·  12   =  MT²

                                                           36  =  MT²

Therefore,  MT  =  6

Similarly, for the right triangle:  MU  =  6

Finally:  TU  =  12 

Two circles intersect at A and B.

A common external tangent is tangent to the circles at T and U, as shown.

Let M be the intersection of line AB and TU. If AB = 9 and BM = 3, find TU.

answer see: https://web2.0calc.com/questions/welp-number-3