Peter C. answered • 09/08/17
Tutor
New to Wyzant
Experienced math teacher
We use the distance formula which says...
d = sqrt( (x2 - x1)2 +(y2 - y1)2)
Label C as (x1, y1) and Label D as (x2, y2) and plug them in
d = sqrt( (7 - 1)2 + (4 - -9)2)
= sqrt( 62 + 132 )
= sqrt( 36 + 169)
= sqrt(205)
Which is about 14.32 units.
