28. Five mark exercise problems VI

\(ABCD\) is a cyclic quadrilateral such that \(\angle A = (4y + 20)^{\circ}\), \(\angle B = (3y - 5)^{\circ}\), \(\angle C = (4x)^{\circ}\) and \(\angle D = (7x + 5)^{\circ}\). Find the four angles.

 

Answer:

 

\(\angle A =\) $i\mathrm{°}$

 

\(\angle B =\) $i\mathrm{°}$

 

\(\angle C =\) $i\mathrm{°}$

 

\(\angle D =\) $i\mathrm{°}$