Two corners of a triangle have angles of # ( pi )/ 2 # and # ( pi ) / 4 #. If one side of the triangle has a length of # 1 #, what is the longest possible perimeter of the triangle?

1 Answer
Jun 4, 2016

Longest possible perimeter is #3.4142#.

Explanation:

As two angles are #pi/2# and #pi/4#, third angle is #pi-pi/2-pi/4=pi/4#.

For longest perimeter side of length #1#, say #a#, has to be opposite smallest angle which is #pi/4# and then using sine formula other two sides will be

#1/(sin(pi/4))=b/sin(pi/2)=c/(sin(pi/4))#

Hence #b=(1xxsin(pi/2))/(sin(pi/4))=(1xx1)/(1/sqrt2)=sqrt2=1.4142#

and #c=1#

Hence longest possible perimeter is #1+1+1.4142=3.4142#.