Find sin (45+theta) - cos(45-theta)

Sin ( 45° + t ) - cos ( 45° - t ) = 
= sin 45° cos t + cos 45° sin t - ( cos 45° cos t + sin 45° sin t ) =
= sin 45° cos t + cos 45° sin t - cos 45° cos t - sin 45° sin t =
( sin 45° = √2/2,  cos 45° = √2/2 ) =
= √2/2 cos t + √2/2 sin t - √2/ 2 cos t - √2/2 sin t = 0

Def is a scalene triangle