If bc = 6.5, cd = 7.8, and ad = 12.2, find ab to the nearest tenth.

This can be solved using the angle bisector theorem. Note that line segment AD is the angle bisector of triangle DAB from angle DAB. Therefore, we know that the ratios  and  are equal. Solving, we get . Cross multiplying, we get , and solving this equation we get . 10.2 is your answer.

Check the internet ok that will