Answer:
Step-by-step explanation:
Given is a triangle DEF as shown in the picture with D having coordinates as
D as such has coordinates as (-1,3)
When rotated about 90 degrees counterclockwise we see that
D will move to third quadrant
Hence both x and y have to be negative
Since 90 degrees rotated magnitudes of x and y will be changed
HEnce new coordinate of D = D'=(-3,-1)
Whenever (x,y) is rotated about origin counterclockwise new coordinate would be (-y,x)
Hence here (-3,-1)
