I was thinking that the Telemaster uses a lifting horizontal stablizer? That might make it interesting.

Formulas:

Measure the areas of the original design's vertical and hoizontal surfaces.

A lot of sport models use about 1/3 of the horizontal area for the vertical area. To figure the angle the following example shows the basic math for such a ratio.

Once the ratio of vertical to horizontal surface area is determined, it becomes a simple math problem to calculate the angle of the V, as well as the area.

The basic trigonometric function is : Sin^2  + Cos^2  = 1

{This should read Sine squared Theta + Cosine squared Theta equals one}

If we want the ratio to be 1:3, then Theta () needs to result in:
0.25 + 0.75 =1

The square root of 0.25 is 0.5, and the square root of 0.75 is .866

The arc-sine or inverse of the sine function of 0.5 gives 30 degrees.
The arc-cosine or inverse of the cosine function of .866 also gives 30 degrees.

Thus, for an equivalent ratio of 1:3 for the vertical to horizontal area, the angle of each half of the V-tail need to be 30 degrees above the horizontal plane. Since the angle between the V is typically called out, it becomes 120 degrees (180 – 2(30)).

There is some disagreement as to the area required. They range from:
a) using the same size as the existing horizontal stab area
b) using the projected stab area of the V the same as original
c) using the same total area as the combined area of the original tail
d) using the square root of the sum of the squares of areas of the vertical and horizontal

Gliders often use very acute angles (90-110 degrees), because they need a lot of rudder authority.
Pylon racers often use (110-120), I’ll reserve comment as to why.