As you may already know, you can only calculate the relative lengths and NOT the actual side lengths of a triangle when you are given all 3 angles.
As an example, let's take triangle ABC in which angle A = 50°, angle B = 60° and angle C = 70°.
For calculating the third side (BC), we need to use two Pythagorean Theorem equations.
side x² = 1.1547² - 1² = .33333 side x = 0.57735
Let's "neaten up" those numbers just a bit, by multiplying each of those sides by the reiprocal of the shortest side.
By doing this we get:
To check if your calculations are correct, go to this calculator, select "3 sides", enter 1, 1.1305 and 1.2266 then click "calculate".
Easier Method
Look up the sine values for each of the angles: Sine 35° = 0.57358 Sine 50° = 0.76604 Sine 95° = 0.99619 And that's it!
Granted we could "neaten up" the numbers by multiplying them by the reciprocal of the smallest side 1 ÷ .57358 = 1.743436
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