a rhombus has an area of 50 cm^2 and an internal angle of size 63 degrees. Find the lenth of its sides.

please show all working out.

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- May 26th 2010, 02:47 AMTessarinaarea of triangles 2
a rhombus has an area of 50 cm^2 and an internal angle of size 63 degrees. Find the lenth of its sides.

please show all working out. - May 26th 2010, 04:32 AMskeeter
- May 26th 2010, 01:12 PMTessarina
i worked out the other one, but with this one i just can't seem to get the right answer.

i think iam doing something wrong, - May 26th 2010, 01:50 PMskeeter
- May 26th 2010, 11:30 PMTessarina
could you just show me what working out you would do?

- May 27th 2010, 01:30 AMProve It
Try using the formula

$\displaystyle A = ab\sin{\theta}$.

Like Skeeter said, show us what working you have done. We are not here to do your work for you. - May 27th 2010, 01:57 AMTessarina
this is the working out i did:

A= 50cm^2

1/2 x a x c x sin63= 50

acsin63= 100

-and thats all i got to. - May 27th 2010, 02:01 AMProve It
- May 27th 2010, 02:09 AMTessarina
then do i work it out by going--

2asin63=100

2a=100/sin63

2a=112.23

a=56.11

but then if i double that to get the area of the whole rhombus i get

112.23

which is the wrong answer.

the answer is: 137.0cm^2

what am i doing wrong? - May 27th 2010, 02:13 AMProve It
- May 27th 2010, 02:18 AMTessarina
then it would be-

a^2= 100/sin63

a= 10.59

so if that is the length of one side, how do i then work out he are of the entire rhombus? - May 27th 2010, 02:20 AMProve It
- May 27th 2010, 02:25 AMTessarina
I got it!

Thank you so much.

i realised then that i was looking at the wrong answer in the back of the book, thats why it wasnt making sense.

Thank you :)