Let the parallel line with point C as AD intersect with the extension line of BA at point E, first prove that the quadrilateral ADCE is a parallelogram, and get CD=AE, CE=AD=6, and then prove CE⊥BC. Then, according to Pythagorean theorem, get BE2=BC2+CE2= 100, and then get AB+.
answer
Solution: As shown in the figure, point C is the parallel line of AD, and the extension line of intersection BA is at point E. 。
∫AB∨CD,CE∨AD,
The quadrangle is a parallelogram,
∴CD=AE,CE=AD=6.
∵AD⊥BC,CE∥AD,
∴CE⊥BC,
∴BE2=BC2+CE2=82+62= 100,
∴BE= 10,
∴AB+CD=AB+AE=BE= 10.