Here's the question you clicked on:
virtus
In triangle ABC, CD bisects the angle BCA and D lies on side AB. Angle c = 60 degrees, AC = 8cm and BC = 6cm
calculate the length of AB, giving your answer correct to one decimal place
Are you allowed to use the law of cosines?
use the law of cosines.... \(\large (AB)^2=(AC)^2+(BC)^2-2(AC)(BC)cosC \)
I'm not sure what DC has to do with anything...put there to confuse, I guess? I can't think of a better way to do solve it.
@dpaInc I tried to use cosine rule, but i don't think that is how you do it cause you get a whole no. as an answer and the question asks you to round off to 1 d.p Furthermore i checked the solution booklet and it says the answer is 7.2 cm
...I didn't get a whole answer, but I also didn't get 7.2. Hmm...
No, I did get 7.2, never mind. c^2 = 6^2 + 8^2 - 2(6)(8)cos(60)
oh i must have made a mistake then! THANKS
I get 13.8 for some reason
put the calculator in degrees measure.. .