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