A triangle has corners at (4 , 5 ), (3 ,2 ), and (5 ,3 ). What is the radius of the triangle's inscribed circle?

1 Answer

The radius r=0.654929" "unit

Explanation:

We use the formula for radius of inscribed circle in a triangle

r=sqrt(((s-a)(s-b)(s-c))/s)" " where a,b,c are the sides of the triangle and s is half of the Perimeter's measure.

s=(a+b+c)/2

Using distance formula we compute for the sides

Let side a the distance from (4, 5) to (3, 2)
Let side b the distance from (5, 3) to (3, 2)
Let side c the distance from (4, 5) to (5, 3)

a=sqrt10
b=sqrt5
c=sqrt5

s=(a+b+c)/2=(sqrt10+sqrt5+sqrt5)/2=(sqrt10+2sqrt5)/2

Compute r

r=sqrt(((s-a)(s-b)(s-c))/s)

r=sqrt((((sqrt10+2sqrt5)/2-sqrt10)((sqrt10+2sqrt5)/2-sqrt5)((sqrt10+2sqrt5)/2-sqrt5))/((sqrt10+2sqrt5)/2))

r=0.654929" "unit

desmos

God bless....I hope the explanation is useful.