The positive number 2 is 28 numbers less than 30 in, and because you pointed out 30 is in inches I’m guessing 2 is in inches also.
First you would have to find the third angle in the triangle which you would do by adding 63+61 and subtracting the resulting number from the total degrees in a triangle. From there, you would calculate x and y using the knowledge that angles on a line equal 180.
1 centimeter is equivalent to 10 millimeters. So 15x10=150 millimeters.
Hope this helped! :D