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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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.
... use the parallelogram area formula provided in your previous post.Quote:
Originally Posted by Tessarina
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,
can't fix it if we don't know what you tried ...Quote:
Originally Posted by Tessarina
could you just show me what working out you would do?
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.
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.
You're almost there. Just remember that in a rhombus, all sides are equal.Quote:
Originally Posted by Tessarina
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?
It should actually beQuote:
Originally Posted by Tessarina
$\displaystyle a^2\sin{\theta} = 100$.
BTW you only halve when you are finding the area of a triangle. Since it's half of a parallelogram.
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?
Oops, it should have actually beenQuote:
Originally Posted by Tessarina
$\displaystyle a^2\sin{63^{\circ}} = 50$.
You already know the area of the rhombus, it's $\displaystyle 50\,\textrm{cm}^2$. You're trying to find the side length, i.e. $\displaystyle a$.
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 :)
