Question

I entered the wrong coordinates in a previous question, i corrected down below.
How do I determine which two triangles on a graph are congruent. ∆QRS and ∆DEF or ∆ABC and ∆XYZ.
i found the coordinates of both sets:
QRS Q(-2,5), R(-2,1), S(-5, 1)
DEF D(5,-6), E(5,-2), F(2,-2)
or
ABC A(4,5), B(6,2), C(2,2)
XYZ X(-4,-5), Y(-6,-2), Z(-2,-2)
Steve replied to use the distance formula but i don't know what that is.

Answer 1

If you have two points (a,b) and (c,d)
then the distance between them is
√( (a-c)^2 + (b-d)^2 )
(notice that since we are squaring the difference, it really would not matter in which direction you are subtracting)

e.g. for R(-2,1) and S(-5,1)
RS = √( (-2+5)^2 + (1-1)^2 )
= √( 9 + 0)
= 3

Repeat for the other two segments of the first triangle and the three segments of the second triangle.
If you can find 3 equal pairs, then the triangles are congruent, since you have 3 corresponding sides equal.

Answer 2

Thanks.
I used the distance formula but i am getting that both sets are congruent but there is only one answer and I don't know what i did wrong.