30%
percent means parts out of 100 so 30%=30/100=3/10
42 is 3/10 of x
'of' can be translated to multiply
42=3/10 times x
multiply both sides by 10/3 to get rid of fraction
420/3=x
140=x
the number is 140
They are similar. I don't remember what it is called but it is 100% ALWAYS true that the angles of a triangle must add up to 180 degrees. Always. If you have two angles, that are 60 degrees, the other must always be 60. again, always. So, They are similar by their angles.
Her bonus would be four dollars. I hope this helped!