A few days ago
☮ klaudia

# How do i find the length of the sides of triangle ABC?

A (3,1), B (-1,1), C (-1,-2)

It says to use the distance formula, but I only know how to do that with two coordinate pairs.

A few days ago
Saya

if you know how to use distance formula then you can easily find the distance of the triangle.

try to find the distance AB, BC and CA, then all you got to do is add them up.

Formula is square root of {(x2-x1)^2 + (y2-y1)^2}

which has come from the Pythagorean theorem. (A^2 = B^2 + C^2)

So, let’s find the distance.

distance of AB – A(3, 1), B(-1, 1)

sqrt{(-1 – 3)^2 + (1 – 1)^2} = sqrt {(-4)^2 + 0^2} = sqrt 16 = 4

distance of BC – B(-1, 1), C(-1, -2)

sqrt[{(-1) – (-1)}^2 + ((-2) – 1)^2] = sqrt{(0^2)+(-3)^2} = sqrt 9 = 3

distance of CA – C(-1, -2), A(3, 1)

sqrt[{3 – (-1)}^2 + {1 – (-2)}^2] = sqrt {(4)^2 + (3)^2} = sqrt 25 = 5

As you can see from above, distance of AB, BC and CA are 4, 3, 5. Now add them up to find the length if the sides of triangle ABC which is equal to 12.

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A few days ago
dbu_44240
yeah, do the distance formula between each two points : A to B, A to C and B to C .

there u go.

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A few days ago
VictoriaRose
try the distance formula between AB then BC then AC

you will then have a triangle

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