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Mathematics: Running fixes
The sum of angles in a triangle is 180°
Draw a triangle ABC, then draw a line DAE parallel to line BC.
Now, angles α and
β in the triangle equal angles DAB and EAC, respectively.
Therefore, the sum of angles in the triangle is 180° : a straight line.
“Doubling the angle” yields two equal angles
So, α + δ + γ = 180°
|α = 30° , β = 60° |
thus γ = 30°
α + 180 - β + γ = 180°
2α = β
α + 180 - 2α + γ = 180°
180° - α + γ = 180°
-α + γ = 0
γ = α
Two equal angles render an triangle isosceles
In the triangle on the right, α = γ and β = 2α.
By constructing the bisector h of angle β we create two little triangles in which x=y.
Next math chapter: Distance of horizon
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