What is the missing number in the table?

The missing number is 16.

Step-by-step explanation:

The ratio between x and y is 1:4. 4 times 4 is 16. Hope this helped! :)

point a is the center of the circle that passes through points e, f, and g and the center of the circle that passes through points x, y, and z.

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.