A triangle has sides A, B, and C. Sides A and B are of lengths #4# and #7#, respectively, and the angle between A and B is #(3pi)/4 #. What is the length of side C?

1 Answer
Pietro P.
Jun 1, 2016

Side C=10.1 units

Explanation:

This question can be used using the law of cosines, and equation used to figure out information regarding either side length or angle of a non right triangle. The formula is #c^2#=#a^2# +#b^2#-2(a)(b)cos(#angleC#). So plugging the info in, we get #c^2#=#4^2#+#7^2#-2(4)(7)cos(#3pi/4#). Solving this with a calculator, we get #c^2#=102.6. Squaring that values, we get the finally of 10.1 units.

P.S. I assumed that the angle was in radians.

Related questions
See all questions in The Law of Cosines
Impact of this question
1693 views around the world
You can reuse this answer
Creative Commons License