Given a perpendicular to AC, what is the area of...
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The area of rightangled triangle BCD = 1/2*BD*CD
1) Angle BAD = 69°
No information about BD and CD. Insufficient.
2) BD = CD
Since the traingle ABD is a rightangled traingle, we have BD^2 = AB^2 - AD^2 => BD^2 = 11^2 - 4^2 = 121 - 16 = 105.
We know that the area of rightangled triangle BCD = 1/2*BD*CD = 1/2*BD^2; since BD = CD
The area of the rightangled traingle BCD = 1/2*BD^2 = 1/2*105 = 105/2. Sufficient.
The correct answer: B
Hope this helps!
-Jay
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