~kites have adjacent sides equal~
x = 3x-12
move 3x to the other side as a negative number
-2x = -12
divide both sides by -2
-12 divided by -2 is 6
so, x is equal to 6
but, we aren't done yet because the questions asks for the value of angle b
substitute the value we found into the equation for angle b
3(6)-12
36-12
24
so, angle b has a value of 24 degrees