D and E are points on the sides AB and AC respectively of a ΔABC such that DE || BC.

If AD = 3.6 cm, AB = 10 cm and AE = 4.5 cm, find EC and AC.
Given: AD = 3.6 cm, AB = 10 cm and AE = 4.5 cm.
Applying Thale’s Theorem,
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⇒ ![]()
⇒
[∵ DB = AB – AD ⇒ DB = 10 – 3.6 = 6.4]
⇒ ![]()
⇒ EC = 8
Now, AC = AE + EC
⇒ AC = 4.5 + 8 = 12.5
Hence, EC = 8 cm and AC = 12.5 cm