Answer:
x=16
angle 3=51
angle 4=39
Explanation:
1) since angles 1,2 and 3,4 are vertical from each other we can use vertical angle therom (vertical angles are equal to each other)
angle 1 and 2 make a 90 degree angle
so
3x+3+39=90
3x+42=90
3x=48
x=16
lets plug in "16" as "x"
3(16)+3=51
IF you wanted to find out what angle 3 and 4 is
angle 3=51(opposite of angle 1)
angle 4= 39 opposite of angle 2