A triangle has sides A, B, and C. The angle between sides A and B is π2 and the angle between sides B and C is π12. If side B has a length of 12, what is the area of the triangle?

1 Answer
Dec 30, 2015

Area=S=19.292

Explanation:

If the angle between A and B is π2 then the triangle is a right one and its area is:
S=AB2

Since the angle between B and C is known and the length of B also is known, we can find A in this way:
tan(π12)=opposed cathetusadjacent cathetus
So tan(π12)=AB => A=Btan(π12)

Finally,
S=B2tan(π12)2
S=1220.2679492=19.292