Question

opposite angle of cyclic quadrilateral is in the ratio of 4:5 find these angles....

With explanation....

Answer 1

in a cyclic quadrilateral the sum of opposite angles is 180°.
let these angles be 4x,5x
$4x + 5x = 180 \\ 9x = 1801 \\ x = 20 \\ \\ 4x = 80 \\ \\ \\ 5x = 100$
please follow me

Answer 2

sum of opposition angle = 180°

so let the first angle = 4x
and second be = 5x

so ATQ,

9x = 180
x = 20°

so 1st is 4x = 80°
and 2nd = 5x = 100°

hope this helps you!