Thursday

September 18, 2014

September 18, 2014

Posted by **kim** on Wednesday, April 15, 2009 at 3:49pm.

- math -
**Reiny**, Wednesday, April 15, 2009 at 8:44pmWow, of the four possible centres of a triangle, the incentre is the hardest to find.

And with those awful numbers ......

by definition, it is the point which is equidistant from the 3 sides.

let the incentre be (p,q)

recall that the distance from a given point (a,b) to the line Ax + By + C = 0

is │Aa + Bb + C│ / √(A^2 + B^2)

so find the equations of each of the 3 sides, and change them to the general form Ax + By + C = 0

then form 3 different expressions for the distance to the lines, they are all equal,

so set the first equal to the second,

and the first equal to the third.

Good luck with those numbers, I certainly don't feel like doing it.

**Answer this Question**

**Related Questions**

math - if you have the triangle ABC with the points A(47,100) B(-1273,203) and C...

Geometry - ABC is a triangle with area equal to 20 . The incircle of triangle ...

HELP!!!!RIGHT NOW!!!! - Which set of side lengths shows similar triangles? (1 ...

math - with only have the points on a triangle how would you determine the ...

geometry - The medial triangle of a triangle ABC is the triangle whose vertices...

Math - Which set of side lengths shows similar triangles? Triangle ABC : 40, 20...

Math - In triangle ABC, points D,E,F are on sides BC,CA,AB respectively such ...

help math - In triangle ABC, points D,E,F are on sides BC,CA,AB respectively ...

Hard Geometry Problem - Hi guys. I need a lot of help on this. "Equilateral ...

Math - ABC is a triangle with ∠BAC=60∘. It has an incircle Γ, ...