Proof of Inscribed circle in Right angle triangle

circlesgeometrytriangles

Question asks to

Prove the diametre of a circle inscribed in a right angle triangle is equal to the sum of the two shorter sides minus that of the hypotheneus

I was able to create a diagram (like the one below) and attempted to create as many congruent triangles as I could with the right angle triangle's sides so I could find some way to prove them similar in some way to the radius but I have been unable to link them. Can you please help?

With the image ignore the numbers and listings they are irrelevant to the question

With the image ignore the numbers and listings they are irrelevant to the question. Just here as a reference

Best Answer

$AB = AF + FB$

$BC = BD + DC = FB + r$

$CA = CE + EA = r + AF$

$BC + CA = 2r + AF + FB = 2r + AB$

Diameter = $2r = BC + CA - AB$

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