A triangle has two corners with angles of # pi / 2 # and # ( pi )/ 8 #. If one side of the triangle has a length of #13 #, what is the largest possible area of the triangle?

1 Answer
Apr 16, 2018

The area is #169/(2(sqrt(2)-1))~~204#

Explanation:

Original Drawing

If one of the angles of the triangle is #pi/2#, it is a right triangle. The measure of the third angle of the triangle must be #pi/2-pi/8=(3pi)/8#. The shortest side of this right triangle will be the leg that is opposite the angle measuring #pi/8#. Let #x#= the length of the longer leg. The area, #A#, of the triangle will be

#A=13/2x#

From trigonmetry

#x=13/tan(pi/8)#

So

#A=13^2/(2tan(pi/8))=169/(2(sqrt(2)-1))~~204#