In the triangle, is x>90?
1) a^2+b^2<15
2) c>4
Pls explain. Thanks.
OA is C
Triangle DS - Set11 Q20
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In the triangle, is x>90?
I assume a,b,c are sides & x is one of the angle
1) a^2+b^2<15
if a^2 + b^2 =15 then hypotenuse is root(15) in that case one angle will be 90 degs but here the hypotenuse may be root 15, less than that or more that so X=90, X<90, X>90 INSUFF
2) c>4
c>4 then
we cant say, other sides are not known
combine: we have a^2+b^2<15 & c>4 so so it cannot be a right angle hence & we can say that if c=root 15 then angle oppsite to it will be 90 degs , now imagine if we increase c from root(15) while a & b are the same then the angle opposite to it will increase hence it will be greater than 90 degs.
suff C
I assume a,b,c are sides & x is one of the angle
1) a^2+b^2<15
if a^2 + b^2 =15 then hypotenuse is root(15) in that case one angle will be 90 degs but here the hypotenuse may be root 15, less than that or more that so X=90, X<90, X>90 INSUFF
2) c>4
c>4 then
we cant say, other sides are not known
combine: we have a^2+b^2<15 & c>4 so so it cannot be a right angle hence & we can say that if c=root 15 then angle oppsite to it will be 90 degs , now imagine if we increase c from root(15) while a & b are the same then the angle opposite to it will increase hence it will be greater than 90 degs.
suff C
Regards
Samir
Samir