Q.1. In the figure given below,
BAC-90° and AD
BC. Then,
Answers
Step-by-step explanation:
In △ABD,
AB
2
=BD
2
+AD
2
(Pythagoras theorem)
In △ACD,
AC
2
=CD
2
+AD
2
(Pythagoras theorem)
Add both the equations,
AB
2
+AC
2
=BD
2
+AD
2
+CD
2
+AD
2
BC
2
=BD
2
+AD
2
+2BD×CD−2BD×CD+2AD
2
(Apply pythagoras theorem to triangle ABC)
BC
2
=(BD+DC)
2
−2BD×CD+2AD
2
BC
2
=BC
2
−2BD×CD+2AD
2
AD
2
=BD×CD
Answer:
The question is incomplete..
In the figure given below,∠BAC=90 and AD⊥BC, then AD^2 = BD×DC. Prove that the above given statement is true.
Is this the question you meant..?
Step-by-step explanation:
In △ABD,
AB^2 = BD^2 + AD^2 (Pythagoras theorem)
In △ACD,
AC^2 = CD^2 + AD^2 (Pythagoras theorem)
Add both the equations,
AB^2 + AC^2 = BD^2 + AD^2 + CD^2 + AD^2 + BC^2 = BD^2 + AD^2 + 2BD × CD − 2BD × CD + 2AD^2 (Apply pythagoras theorem to triangle ABC)
BC^2 = (BD + DC)^2 − 2BD × CD + 2AD^2
BC^2 = BC^2 − 2BD × CD + 2AD^2
AD^2 = BD × CD
Hence Proved
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