Question 1084406
Since we know 2 shorter sides, we need to calculate the hypotenuse:
sqrt(6^2+8^2) = 10
:
Now we know all three sides, we can use Heron's formula to find the area. 
Our perimeter is 10+8+6 = 24 and 24/2 = 12:
sqrt(12(12-10)(12-8)(12-6)) = 24 This is the area of the triangle
:
Radius of the inscribed circle:
(2a)/p, where a is the area and p the perimeter:
(2*24)/24 = 2 <--this is the radius of your incircle.
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Let me give you a shortcut in case you get another problem like this:
radius = (a+b-c)/2
r = (6+8-10)/2 = 2
The explanation for this method is lengthy, but the formula is short and sweet ;-)