Question

∆ABC is translated 6 units up and 3 units left to create ∆A'B'

c. If vertex A is at (-1, 2) and vertex B is at (1, 5), then where is vertex A' at vertex and where is vertex B' at ?

Answer 1

Keep in mind that the positive directions of the two axis are: upwards for the y axis and rightwards for the x axis.

So, translating a point 6 units up means to go 6 units along the positive direction on the y axis. For this reason, the new y coordinate will be 6 units more than the old one.

Similarly, going 3 units left means to decrease by 3 the x coordinate, because we're following the negative direction.

So, to recap, this transformation maps
`(x,y) \to (x-3, y+6)`

This means that the two points become

`A = (-1, 2) \implies A' ( -4,8),\qquad B = (1,5) \implies B' = (-2,11)`