Question

help plzzz Angle ABC is formed by segments AB and BC on the following coordinate grid:

A coordinate grid is shown from positive 6 to negative 6 on the x axis and from positive 6 to negative 6 on the y axis. A line segment AB is shown with A as ordered pair 1, negative 1 and B as ordered pair 5, negative 4. Another line segment BC is shown with C as ordered pair 1, negative 4.

Angle ABC is rotated 90 degrees counterclockwise about the origin to form angle A′B′C′. Which statement shows the measure of angle A′B′C′?

m∠ A′B′C′ = 90 degrees
m∠ A′B′C′ = m∠ABC
m∠ A′B′C′ = 180 degrees
m∠ A′B′C′ = 2 ⋅ m∠ABC

Answer 1

Hey!

When you're rotating 90 degrees counterclockwise about the origin, your points will go from
A(x, y) to A'(-y, x)

Answer 2

You can find the new rotated image however, it's not necessary.

When you rotate something, the shape and size stay the same. So what do you think happens to the angle? Do you think the angle will increase, stay the same, or decrease?

Answer 3

The angle should stay the same size.

Answer 4

Exactly! And which answer choice would that be?

Answer 5

ohh, okay I get it now! Thank you so much for the help! I have got my answer.

Answer 6

Of course! It was my pleasure :)