Question 892904
In ∆ABC, if the length of sides a, b, and c are 3.5 centimeters, 5.5 centimeters, and 6 centimeters respectively, what is m∠C to two decimal places?

{{{drawing(400,240,-.5,6.5,-.5,3.7,

triangle(0,0,4.5,3.1622776,6,0),locate(0,0,A),locate(6,0,B),

red(arc(4.5,3.1622776,2.2,-2.2,215,295)),locate(3.9,2.6,"80.28°"),
locate(4.4,3.45,C),locate(2.8,0,c=6),locate(5.4,1.6,a=3.5), locate(1.7,2,b=5.5) )}}}{{{matrix(9,1,
LAW,OF,COSINES,"",cos(C)=(a^2+b^2-c^2)/(2ab),"",cos(C)=(3.5^2+5.5^2-6^2)/(2(3.5)(5.5)),"",C="80.28°")}}}
<pre>Edwin</pre>