Sine and Cosine rules

[squance]

Hi! I'm squance's sister and i have question about the sine and cosine rule that i would like some help with.

Question:
The adjacent sides of a parallelogram are 9 cm and 11 cm. One of its angles is 67*. Find the length of the longer diagonal, correct to two decimal places.

i keep getting close to the answer but i can't actually get the answer.

Question 2
In triangle ABC, <ABC=35*, AB=10cm and BC=4.7. Find, correct to two decimal places:
<ACB.

this one, i'm not sure what i'm doing wrong because i keep getting answers that are not alike to the answers in the back of the book.

thanks

[squance]

oops...um..i posted the wrong question! sorry..i could solve that problem but i can't solve this question:

in the triangle ABC, <ACB=34*, AC=8.5cm and AB=5.6cm. Find, correct to two decimal places:
BC in each case.

sorry about that...i guess i was a bit tired.

oh. and i still can't solve the first question

thanks for trying the other question..but umm..its not right..but thanks anyway

[Flaming_Arrow]

is BC = 10 cm?

[squance]

yep thats one of the answers!! Thanks How did you get it??? oh and how would you go about finding the other answer???

[Flaming_Arrow]

first workout





then workout

[squance]

thanks

[Flaming_Arrow]

[squance]

thanks..but where did you get the 113 degrees from???

[Flaming_Arrow]

opposites angles of a parallelogram are equal, so

[squance]

oh! thanks!!! i get it now