Question

Figure EFGH on the grid below represents a trapezoidal plate at its starting position on a rotating surface.

The plate is rotated 90° about the origin in the counterclockwise direction. In the image trapezoid, what are the coordinates of the endpoints of the side congruent to side EH?

Answer 1

(8, 4) and (5, 2)

(4, -8) and (2, -5)

(-8, -4) and (-5, -2)

(-8, -4) and (-5, -7)

Answer 2

@ash2326

Answer 3

@.Sam.

Answer 4

Start with an easier question. What are the coordinates of point E right now...before rotating?

Answer 5

(-4,8)

Answer 6

ok. when we rotate 90degrees counterclockwise....up becomes left....and left becomes down. To move from the origin to that point -4,8 I have to go left 4 and up 8. AFTER the rotation I'll have to go down 4 and left 8 from the origin. If I go down 4 and left 8 from the origin, on what point am I not?

Answer 7

am i now? (sorry typo)

Answer 8

(4, -8) and (2, -5)

Answer 9

We're not ready for the final answer yet. Point E does not move to (4,-8). Start at the origin. Move down 4 and left 8. Where are you now? Not (4, -8)

Answer 10

(4,-12)

Answer 11

Starting at the origin means starting at 0,0. Start at 0,0. Move down 4 and left 8. Where are you? I have no idea where you got 12.

Answer 12

or the other way around

Answer 13

(-8,-4)

Answer 14

Yes! So we know the answer is C or D. Now we just have to figure out where the H point goes. Before rotating, to get from the origin to H we go left 2 and up 5. Rotating 90 degr counter clockwise...left becomes down and up becomes left. So we start at the origin and go down 2 and left 5. Where are we?

Answer 15

(-5,-2)