Do you know the law of cosines?
Can you use the arccosine function?
Let the sides of a triangle have the respective lengths a=3, b=5,c=6. The respective angles opposite a, b, and c have A, B, and C radian measures.
Using your graphing calculator determine A, B, and C rounded off to six digits to the right of the decimal point. Verify your answers by checking whether A+B+C = ∏. Explain any discrepancy. I'm having a tough time figuring this out .. Please help.
Using law of cosine,
In the same way,
Now, calculate for angle C
Now check,
A + B + C = 0.522315 + 0.981765 + 1.637512
= 3.141592 radians
So,
Since the actual value of but rounded off for six digits, it is 3.141593 and our answer is 3.141592, so the difference between actual value and our answer is 0.000001, that is negligible.