Question

If in two triangle ABC and DEF, ∠A = ∠E, ∠B = ∠F, then which of the following is not true?

(a)\[\frac{BC}{DF} = \frac{AC}{DE}\]

(b)\[\frac{AB}{DE} = \frac{BC}{DF}\]

(c)\[\frac{AB}{EF} = \frac{AC}{DE}\]

(d)\[\frac{BC}{DF} = \frac{AB}{EF}\]

Options

• \[\frac{BC}{DF} = \frac{AC}{DE}\]
• \[\frac{AB}{DE} = \frac{BC}{DF}\]
• \[\frac{AB}{EF} = \frac{AC}{DE}\]
• \[\frac{BC}{DF} = \frac{AB}{EF}\]

Answer 1

 In ΔABC and ΔDEF

`∠ A = ∠ E`

`∠ B = ∠ F`

∴ ΔABC and ΔDEF are similar triangles.

Hence `(AB)/(EF)=(BC)/(FD)=(CA)/(DE)`

Hence the correct answer is (b).