Question

3)June 2019-In the diagram below of AABC, D is a

point on BA, E is a point on BC, and DE is drawn.
If BD = 5, DA= 12, and BE = 7, what is the length of
BC so that AC || DE?

Answer 1

23.8

Explanation:

Answer 2

BC = 23.8

Explanation:

See the diagram attached.

Given AC ║ DE and BD = 5, DA = 12 and BE = 7.

We have to find BC.

Since, AC ║ DE, so, Δ ABC and Δ DBE are similar.

If two triangles are similar then the ratio of their corresponding sides remains the same.

Hence,
`(BD)/(BA) = (BE)/(BC)`

⇒
`(5)/(12 + 5) = (7)/(BC)`

⇒
`BC = (7 * 17)/(5) = 23.8` (Answer)