Well you need to find the equation of a line
if you prefer the slope point form or the two point form
I’ll use slope point form
m= tan(theta) = 10/1 = 10
Take any point now, I’ll take (2,20)
y-20 = 10(x-2)
=> y = 10x
Here, y is m and x is p (x-axis and y-axis)
=> m = 10p