An object launched at 65° from the horizontal would have the same range (distance travelled) as an object launched at 25° from the horizontal.
The greatest range you can get when you launch a projectile is to aim it at 45° above the horizon. If you change that angle by something, then the range is shorter by the same amount if you increse OR decrease the angle by the same something.
65° = 45° plus 20°. So the range will be the same if you launch at an angle of (45° minus 20°). That's 25°.
