LA5 marksYear: 2024HardCBSE Class 10
trianglessimilaritycongruenceBPTproof
Question
In the given figure, △FEC≅△GDB and ∠1=∠2. Prove that △ADE∼△ABC.

Solution
1
△FEC≅△GDB⇒∠3=∠4 (CPCT)
+1 mark2
In △ABC, ∠3=∠4⇒AB=AC ...(i)
+1 mark3
In △ADE, ∠1=∠2⇒AD=AE ...(ii)
+1 mark4
Dividing (ii) by (i): ABAD=ACAE⇒DE∥BC (by converse of BPT)
+1 mark5
∠1=∠3 and ∠2=∠4 (corresponding angles). ∴△ADE∼△ABC (AA similarity)
+1 mark