In a triangle ABC , let angle C = 90o . If r is the inradius and R is the circumradius , then 2(r + R) is equal to
a) a+b
b) b+c
​c) a+c
d) a+b+c

Dear Student,

Given, In a triangle ABC,C=900We know that,R=c2sinCR=c2sin900R=c22R=c        ......1And,r=s-ctanC2r=s-ctan9002r=s-ctan450r=s-c2r=2s-2c        ......2Adding equation1 and 2, we have,2R+2r=c+2s-2c2R+2r=c+a+b+c-2c2R+2r=a+b2R+r=a+b

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