Answer:
BE : EC = 1 : 3
Step-by-step explanation:
Consider triangles AKD and EKB. In these triangles
- ∠AKD≅∠EKB as vertical angles;
- ∠ADK≅∠EBK as alternate interior angles;
- ∠KAD≅∠KEB as alternate interior angles.
Then ΔAKD is similar to ΔEKB by AAA theorem.
Similar triangles have proportional corresponding sides:
[tex]\dfrac{AD}{EB}=\dfrac{AK}{EK}=\dfrac{DK}{KB}.[/tex]
Since [tex]\dfrac{DK}{KB}=\dfrac{4}{1},[/tex] then [tex]AD=4BE.[/tex]
Opposite sides in parallelogram have the same lengths, then [tex]BC=AD.[/tex]
Now
[tex]BC=BE+EC,\\ \\BC=\dfrac{1}{4}BC+EC,\\ \\EC=BC-\dfrac{1}{4}BC=\dfrac{3}{4}BC.[/tex]
Find the ratio
[tex]\dfrac{BE}{EC}=\dfrac{\frac{1}{4}BC}{\frac{3}{4}BC}=\dfrac{1}{3}.[/tex]
