In △ABC, AB = c cm, AC = b cm and CB = a cm. If ∠A = 2 ∠B,then which of the following is true?
Answer & explanation
Correct answer: option 4
Let A = 90
\(\angle\)B = 45
As we know,
In \(\Delta \)ABC
\( {(BC) }^{ 2} \) = \( {(AC) }^{ 2} \) + \( {(AB) }^{ 2} \)
= \( {(a) }^{ 2} \) = \( {(b) }^{ 2} \) + \( {(c) }^{ 2} \) ..(1)
If \(\angle\)B = \(\angle\)C
So, AC = AB
b = c
from equation (1)
\( {(a) }^{ 2} \) = \( {(b) }^{ 2} \) + c.c
= \( {(a) }^{ 2} \) = \( {(b) }^{ 2} \) + bc.