# Trigonometry Help Given Angles ABC?

• Jun 7th 2009, 05:52 AM
mr_quick
Trigonometry Help Given Angles ABC?
I need some help with these Trigonometry functions Thank you so much for taking the time to help me

1. If Angle A = 56* 40' and b=22ft. find c.

2. If Angle B = 25* and c = 12 cm find b.

3. If b = 16.3 ft. and a = 21.7 ft. find Angle A.

Thank you so much
• Jun 7th 2009, 09:56 AM
HallsofIvy
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Originally Posted by mr_quick
I need some help with these Trigonometry functions Thank you so much for taking the time to help me

We are to assume that this is a right triangle with right angle C? Otherwise it cannot be done.

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1. If Angle A = 56* 40' and b=22ft. find c.
b is "adjacent" angle A and c is the hypotenuse. cos(A)= b/c so c cos(A)= b, c= b/cos(A)

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2. If Angle B = 25* and c = 12 cm find b.
b is "opposite" angle b and c is the hypotenuse. sin(B)= b/c so c sin(B)= b

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3. If b = 16.3 ft. and a = 21.7 ft. find Angle A.
a is "opposite" and b is "adjacent". tan(A)= a/b so A= arctan(a/b).

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Thank you so much
The first thing you should learn about trig functions is their definition!

sin(x)= "opposite"/"hypotenuse"