Chart, plotting a series at an angle

Hello everyone,

I'm having 2 problems with making a chart

Problem 1:

I'm trying to find a way how to plot series at an angle
This i how that graph should look

Screenshot_3.jpg

Only data i have to begin with is "C" ,(x(вертикално опетрећење)=0, y(чврсточа на смицање)=17) starting point of the line
and angle, (in this case the angle is 18) which determines at what angle with the line continue to x value 400

Problem 2:

I need to find the y value (чврсточа на смицање) when the plotted line series intersects major gridlines at 150, 250 and 350

Is there a way to do it by some math or adding some series to act like gridlines, would be much better then too manually look on the chart and write the new values
(need to automate that process, another chart need those values)

Thanks for your answer, i've found a solution that works perfectly for my case so i might as well share it here if anyone needs its

"This is more of a trigonometry question than a charting question. You basically have a right triangle. At the x=150, height would be

tan(angle) = height/length
tan(18) * length = height

However, you have a y intercept of 17, so we'll need to account for that and add 17 to your height

tan(18) * length + 17 = height
tan(18) * 150 + 17 = height
65.74 = height

Visually inspecting the chart, that looks to be correct.

In XL, the trig functions expect a radian input, so you need to use the RADIANS function to convert from degrees to radians. The XL formula then would be

=TAN(RADIANS(18)*150+17

Once you have that, you could make this dynamic by replacing the 150 with a cell reference

=TAN(RADIANS(18)*A2+17

and then in col A put whatever x-values you want to calculate for. This should then be able to solve both Problem 1 & 2."