For any amount of pure Coffee (no milk), you can put 39 grams of sugar or nearly 10 teaspoons of sugar, as Coffee has no sugar in it. 30ml is a standard espresso size so to be equivalent per ml of liquid you would need to put 3.1 grams of sugar which is less than a teaspoon.
The error is that the student measured the wrong side. Acute angles are less than 90 degrees. So it isn’t possible for the measure to be over 90. The correct measure is 49
