Mathematics

Problem

\triangle ABC

, points

D

AB

and

E

AC

satisfy

DE\parallel BC

. Given

AD=4\,\text{cm}

DB=6\,\text{cm}

and

EC=9\,\text{cm}

, find the length of

AE

. a)

5\,\text{cm}

3.6\,\text{cm}

6\,\text{cm}

4\,\text{cm}