A triangle has corners at #(9 , 2 )#, #(4 ,7 )#, and #(5 ,6 )#. What is the radius of the triangle's inscribed circle?

1 Answer
Apr 7, 2017

The three points lie on a single straight line, so they are collinear and do not form a triangle.

Explanation:

Given #A(4,7), B(5,6) and C(9,2)#,

#m_(AB)=(6-7)/(5-4)=-1#

#m_(BC)=(2-6)/(9-5)=-1#

As the two segments #AB# and #BC# have a same gradient of #-1# and a common point #B#, the three points #A,B and C# are collinear.