A triangle has sides A, B, and C. Sides A and B have lengths of 2 and 5, respectively. The angle between A and C is (11pi)/24 and the angle between B and C is (7pi)/24. What is the area of the triangle?

1 Answer
Mar 15, 2018

The triangle does not exist...
Here's the area anyways:
A= (5sqrt2)/2 un^2 approx 3.54 un^2

Explanation:

Area of the triangle:
A= 1/2a*b*sinC
Let's determine angle C:
(24pi)/24-(7pi)/24-(11pi)/24= pi/4

Area of the triangle:
A= 1/2(2)(5)sin(pi/4)=
A= (5sqrt2)/2 un^2 approx 12.37 un^2

How do I know this triangle particularly does not exist?
Well:
The law of sines states:
SinA/a= SinB/b
Therefore:
B= arcsin((SinA*b)/a)
B= arcsin((Sin((7pi)/24)*5)/2)= undef.
Since Angle B cannot be computed, this triangle does not exist