we can notice x is the sum of half DIA A and half BD

and y is the sum of half DIA A and BD

A. Find diameter A when x= 9..82 cm and y = 11.94 cm.
we replace x=9.8 and y=11.94 on the equations

now we have two equations and two unknows, then we can solve BD from the first equation

and replace on the second to find A

simplify

and solve for A

Value of Diameter A is 15.32 cm
B. find y when diameter A = 30.36 cm and X =23.72 cm
now on the initial equations for x and y we replace A and X

we have two equations, we realize we can simplify the first equation

and we can solve BD

now we replace BD on the second equation

The value of y is 32.26 centimeters