VSA2 marksYear: 2020MediumCBSE Class 10
trianglespythagoras-theoremproof
Question
In Fig. 6, if AD⊥BC, then prove that AB2+CD2=BD2+AC2.

Solution
1
In right △ABD: AB2=BD2+AD2 ... (i)
+0.5 marks2
In right △ADC: CD2=AC2−AD2 ... (ii)
+0.5 marks3
Adding (i) and (ii): AB2+CD2=BD2+AD2+AC2−AD2=BD2+AC2
+1 mark