Question

A parallelogram has a 70 degree angles and sides 6cm and 10 cm long. How long are its diagonals?

Will award medals, fan, best answer etc.

Answer 1

I know that in a parallelogram, the diagonals bisect one another.

Answer 2

Have you learned the Law of Cosines?

Answer 3

Yes, can I apply that here?

Answer 4

c^2 = a^2 + b^2 - 2abcosC

Answer 5

yes (otherwise I would not have mentioned it!?)

ignore the diagonal that "splits" the 70 degree angle
you have
2 sides and an included angle.

Answer 6

Got it thanks