Question

What is the length of DC? (picture)

Answer 1

DC =
`(5)/(2)` = 2.5

since the triangles are similar then the ratios of corresponding sides are equal

`(AC)/(AD)` =
`(BC)/(DE)`

`(7.5+DC)/(7.5)` =
`(8)/(6)` (cross-multiply )

45 + 6DC = 60

6DC = 60 - 45 = 15 ( divide both sides by 6 )

DC =
`(5)/(2)`