Question

What is the size of angle y in the quadrilateral below

Answer 1

Hi,

Explanation:

If you want a method to draw the quadrilateral without calculating angle y

see my picture using a a capable bow.

Answer 2

According to angle sum property of quadrilateral
Sum of all angles = 360
Thus, 40+y+20+y = 360
2y = 300
Therefore y = 150