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Question
It is given that ∆ABC ≅ ∆FDE and AB = 5 cm, ∠B = 40° and ∠A = 80°. Then which of the following is true?
Options
DF = 5 cm, ∠F = 60°
DF = 5 cm, ∠E = 60°
DE = 5 cm, ∠E = 60°
DE = 5 cm, ∠D = 40°
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Solution
DF = 5 cm, ∠E = 60°
Explanation:
Given, ∆ABC ≅ ∆FDE and AB = 5 cm, ∠B = 40°, ∠A = 80°
Since, ∆FDE ≅ ∆ABC
∴ DF = AB ...[By CPCT]
DF = 5 cm
And ∠E = ∠C ...[By CPCT]
⇒ ∠E = ∠C = 180° – (∠A + ∠B) ...[By angle sum property of a ∆ABC]
⇒ ∠E = 180° – (80° + 40°)
⇒ ∠E = 60°
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