Question

Is the answer choice I selected right?!

Answer 1

No. Your answer is not correct. The correct answer is B. See explanation.

Explanation:

The Y coordinates of `A'`, `B'` and `C'` are numbers opposite to the respective coordinates in `A`, `B`, and `C`, so the triangle `A'B'C'` can be made from `ABC` by reflection over `X` axis.

Further, two triangles `ABC` an `A'B'Ç'`, the one when reflected over `x`-axis are always congruent as corresponding sides are equal and hence Answer D is wrong.

Answer 2

`(x,y)->(x,-y)`

Explanation:

Let a corner (vertices) on a triangle be `P`
Let one triangle be `"a and the other triangle "b`

Given that there is a reflection about the x-axis and congruency exists;

then if `P_a->(x_a,y_a)` then the corresponding point on the other triangle `P_b->(x_b,y_b)=(x_a,-y_a)`

In other words the value of `x` for corresponding vertices (corners) will be the same. However, the `y` value in one will be `(-1)xxy` of the other.

So if one corner is `(-1,7)` then the other will be `(-1,-7)`

So we have `(x,y)->(x,-y)`

The `->` means 'maps to' or put another way; they are related in some way and there is some form of 'function' that links them.

Very loosely speaking, function is a mathematical term that can be interpreted as 'formula'