Answer:
Step-by-step explanation:
radius=4 as it is tangent to x-axis.
y co-ordinate of center is 4 so radius=4
eq. of circle is (x-2)²+(y-4)²=4²
or x²-4x+4+y²-8y+16=16
or x²+y²-4x-8y+4=0
.20 or 20. one of those i cant give you the answer because how are u going to learn <span />