does any1 have spare time?

Here's c

We have to use the Law of Cosines, first....let's find angle P....so we have

25^2  = 18^2 + 16^2 - 2(18)(16)cosP   simplify

625 = 324 + 256 - 576cosP      subtract 324 and 256 from both sides and divide both sides by - 576

(625 - 324 - 256) / (-576) = cosP.....and we can use the inverse cosine to find P

cos^-1 (625 - 324 - 256) / (-576) = P = about 94.48 degrees

And now, we can use the Law of Sines to find angle R

So we have

sinR/16 = sinP/25

sinR/16 = sin(94.48)/25   multiply both sides by 16

sinR = 16*sin (94.48)/25  = .638

And using the sine inverse we have

sin^-1(.638) = about 39.64 degrees

And the remaining angle, Q = 180- 94.48 - 39.64 = about 45.88 degrees

This makes sense....the greatest angle is opposite the greatest side, the next greatest angle is opposite the next greatest side, and the smallest angle is opposite the smallest side...

task is : find the angle for the highligthed part of the triangle, and lenght of the small letters , trasnlated as good as i could .http://i59.tinypic.com/hsml5e.jpg  for b)
http://i61.tinypic.com/birxxs.jpg for c)

would be grateful if someone could explain how to do these, have test on this topic tomorrow and i've been abscent for 2 weeks

Here's b

Since the sum of any three angles of a triangle = 180....then angle X must just be given by

X + 70 + 40 = 180    simplify

X + 110 = 180          subtract 110 from both sides

X = 70

And using the Law of Sines we can find side "y"...so we have

12 / sin40  = y/ sin 70     multiply both sides by sin70 and we have

12*sin70 / sin40 = y = about 17.54

Also the remaining side is the same length because angle X and Y are equal...and in a triangle....sides opposite equal angles are themselves equal..!!!

Thus....this is an isosceles triangle....(two equal sides)

thanks alot