Angles of a quadrilateral are in the ratio 3 : 4 : 4 : 7. Find all the angles of the quadrilateral. ​  

Add 3x4x4x and 7x and equate the sum to 360

60,80,80,140

3x+ 4x +4x + 7x = 360 degree (total sum of quadrilateral)
18x = 360 degree
x = 360/18
x = 20 degree.

so, angle with ratio 3x = 3*20 = 60 degree
      ​angle with ratio 4x = 4*20 = 80 degree
      ​angle with ratio 4x = 4*20 = 80 degree
      ​angle with ratio 7x = 7*20 = 140 degree
 

60,80,80and140 is the answer.But you should the question by yourself.Its very very easy question.Don't take my words hardly but its for your betterment purpose.