The vertices of rectangle ABCD are A(-1,0), B(2,0), C(s, t), and D(-1,4). How long is diagonal AC?
A. 2 B. 3 C. 4 D. 5 E. 6
The length of AC will be the same as the length of BD, so all we need to do is plug the coordinates of B and D into the distance formula, which is
X2 is -1
X1 is 2
Y2 is 4
Y1 is 0
so d = 5.
The answer is (D).
source: math.rice.edu
