The circle in the figure has a radius of r and center at C. The distance from A to B is x, the distance from A to D is y, and the length of arc BD is s. Redraw the figure, label it as indicated, and solve the problem. If A = 29°, s = 12, and r = 14, find x.
is this for trig?
@jdoe0001 yes
|dw:1374001057223:dw| notice in the triangle given, you're given the arc, that is the central angle of 12 degrees andd the angle A of 29 degrees the obtuse angle will be 180-(29+12) = 139 degrees
$$\bf { \text{using law of sines}\\ \cfrac{12}{sin(29^o)} = \cfrac{14+x}{sin(139^o)}\\ \cfrac{12\times sin(139^o)}{sin(29^o)} = 14+x\\ x = \cfrac{12\times sin(139^o)}{sin(29^o)} -14 } $$
hmm
darn! I have a typo :/
the opposite side to 29 degrees is 14 :/, not 12
thus $$\bf { \text{using law of sines}\\ \cfrac{14}{sin(29^o)} = \cfrac{14+x}{sin(139^o)}\\ \cfrac{14\times sin(139^o)}{sin(29^o)} = 14+x\\ x = \cfrac{14\times sin(139^o)}{sin(29^o)} -14 } $$
@jdoe0001 Okay, I think I understand thank you!
yw
@jdoe0001 I tried it & the answer is wrong :/ am I supposed to add it to something?
no
retry the calculation, keep in mind you're using Degrees, no Radians so make sure your calculator is in Degrees mode
I get -0.68
hmmm wait a minute, that' make no sense hehe
Oh, I got 5. aha & then for the picture, since s = 12. Would I use s = r * theta to find the central angle of C.
meh, I forgot to close a parentheses, anyhow, yes is 5 rounded up
hmm, "s" is given pretty much, "s" is 12 degrees
Even though 's' is the arc length?
|dw:1374008877370:dw|
Join our real-time social learning platform and learn together with your friends!