Question

In ΔABC, DE || BC so that AD = 2.4 cm, AE = 3.2 cm and EC = 4.8 cm. Then, AB = ?

Options

• 3.6 cm

• 6 cm

• 6.4 cm

• 7.2 cm

Answer 1

6 cm

Explanation:

Since DE || BC, by the Basic Proportionality Theorem (or similarity) `(AD)/(AB) = (AE)/(AC)`. 

Here AC = AE + EC

= 3.2 + 4.8

= 8.0

So, `(2.4)/(AB) = (3.2)/8 = 0.4`, giving AB = `(2.4)/(0.4)` = 6 cm.