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 EF?

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

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

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

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

Answer 1

so write \[A^\rightarrow = \left| A \right| [\cos \theta i + \sin \theta j]\]
when we rotate the vector A bye an angle a(POA) then \[A^\rightarrow = P^ \rightarrow = \left| A \right| [\cos( \theta + \alpha)i + \sin( \theta + \alpha)j]\]
take help of this...................

Answer 2

rotate 90 degree is like reflect thro origin
E from (-4,8) to (4,-8)
F from (-7,5) to (7,-5)


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