The diagonals of a parallelogram have measures of 8 and 10 and intersect at a 60 degree angle. Find the area of the parallelogram.

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- June 16th 2008, 01:12 PMmajik92[SOLVED] parallelograms
The diagonals of a parallelogram have measures of 8 and 10 and intersect at a 60 degree angle. Find the area of the parallelogram.

- June 16th 2008, 01:55 PMMoo
Hello,

See the sketch below...

Hint : use trigonometry in triangle OAD. Everything else is there (Wink) - June 16th 2008, 02:11 PMmajik92
thank you

then that means the height of the triangle is 5√(3) and its base is 10. so the area is 25√(3) making the whole parallelogram's area to be 50√(3). i think that's right - June 16th 2008, 02:15 PMMoo
- June 16th 2008, 02:59 PMmajik92
oops, the height's 2√(3) -> A of triangle 5√(3) -> A of parallelogram 10√(3)

- June 16th 2008, 03:02 PMMoo
- June 16th 2008, 03:42 PMPlato
I notice that this thread is marked ‘solved’.

But in fact it is not. There is no correct solution yet.

What should have been noted from the beginning is: the area of the parallelogram is .

Now . - June 16th 2008, 04:26 PMmajik92
- June 16th 2008, 05:19 PMPlato
- June 16th 2008, 11:06 PMMoo

Area of the parallelogram is twice this one...

Same result as Plato's, slight different method... This was going to be the correct result ~