Plot half circles between 2 points with known radius

[avatar822]

I need excel to plot a half circle between 2 points located on the x axis of a scatter chart with a radius of half the difference between the the 2 points. The plot needs to start on the X axis and extend above it. I actually need 3 half circles which which increase in size to the right of the Y axis.

And then to complicate things further, I need to plot a line that is tangent to the 3 plotted circles and figure out the angle and intercept of that line.

 

[yky]

I need excel to plot a half circle between 2 points located on the x axis of a scatter chart with a radius of half the difference between the the 2 points. The plot needs to start on the X axis and extend above it. I actually need 3 half circles which which increase in size to the right of the Y axis.

And then to complicate things further, I need to plot a line that is tangent to the 3 plotted circles and figure out the angle and intercept of that line.

This is all is needed to plot one half circle. If you want more points between A and B, say, 40 points, you'll need to fill the formulae in the range A3:B43.

Book1
	A	B	C
1	point A	point B	points btw A & B
2	3	8	20
3	3	0
4	3.25	1.089725
5	3.5	1.5
6	3.75	1.785357
7	4	2
8	4.25	2.165064
9	4.5	2.291288
10	4.75	2.384848
11	5	2.44949
12	5.25	2.487469
13	5.5	2.5
14	5.75	2.487469
15	6	2.44949
16	6.25	2.384848
17	6.5	2.291288
18	6.75	2.165064
19	7	2
20	7.25	1.785357
21	7.5	1.5
22	7.75	1.089725
23	8	0
Sheet1

Cell Formulas
Range	Formula
A3:A23	A3	=$A$2+($B$2-$A$2)/$C$2*(ROW()-3)
B3:B23	B3	=(($B$2/2-$A$2/2)^2-(A3-($B$2+$A$2)/2)^2)^(1/2)