Posted by **Lisa** on Tuesday, April 17, 2012 at 8:00am.

Can you show us how to use law of cosines to show that theta equals inverse cosine of (a^2 + b^2 -484)/(2ab) where a^2=(7+xcos a)^2 + (28-xsin a)^2 and b^2=(7+xcos a)^2 + (xsin a -6)^2? Thanks

- Trig -
**Reiny**, Tuesday, April 17, 2012 at 8:59am
Lisa, saw that one last night,

confused about the angle 'a'

in xcosa and xsina.

secondly where does x come in ?

describe your triangle.

I have a triangle with sides a and b and Ø as its contained angle.

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