If you want to multiply a decimal by a whole number, just ignore the decimal point and multiply like normal! Then, bring the decimal point back for the answer. for example 2×0.2
first multiply 2*2=4
and then place the decimal we have one value after decimal so the answer is 0.4
The equation of a circle:

(h,k) - the coordinates of the centre
r - the radius
The midpoint of the diameter is the centre of a circle.
The coordinates of the midpoint:

(x₁,y₁), (x₂,y₂) - the coordinates of endpoints

The centre of the circle is (2,5).
The radius is the distance between an endpoint of the diameter and the centre.
The formula for distance:


The radius is 5.
6.8,6.827,6.86,6.9
1.2,1.203,12.03, 12.301,12.31
It’s in Quadrant I. Because it’s not on the origin and it doesn’t fall on any of the axis