IIT JEE , AIEEE Forum - Mathematics , Analytical Geometry

shaji

ABCD is a quadrilateral where angle B = angle C =120 degrees. AB =3CM BC =4CM CD=5CM WHAT IS ITS AREA

puneet

hii

well there does not seems to be any direct method .. though the question is definitely solvable ...

see draw a line BD .. u can easily find the value of BD by using cosine law ..

once BD is known the angle DBC can also be found ..

and so is angle ABD ..

Now in triangle ABD we can find AD .

so, now all sides are known and the value of area of ABCD can be found easily ..

i hope this helps ..

cheers