A frame is made of two right-angled triangles, ADC ADC\,ADC and ABCABCABC, joined at side ACACAC. Triangle ADC ADC\,ADC has a right angle at DDD, where AD=4.5AD = 4.5AD=4.5 cm and DC=3.2DC = 3.2DC=3.2 cm. Triangle ABC ABC\,ABC has a right angle at AAA, where BC=7.8BC = 7.8BC=7.8 cm.
Calculate the length of ABABAB.
Give your answer to 3 significant figures.