abcd is a special quardilateral are in the ratio 1:2:3:4 measur of the four angles =
let the angles be x, 2x, 3x, and 4x. (ratio is 1:2:3:4)
A quadrilateral has an angle sum of 360
x+2x+3x+4x = 360
10x = 360
x = 36
angles are 36°, 72°, 108° and 144°