Determine, in simplest radical form, the length of AB, if A(-7,4) and B(1,-8).

Question

I need help finding the length of AB in simplest radical form.

Answer 1

A: (-7 , 4) B: (1 , -8) d = diameter

Use the pythagorean theorem

A^2 + B^2 = C^2

C = sqrt ( A^2 +B^2)

C = sqrt ( (Ax-Bx)^2 + (Ay-By)^2)

C = sqrt( (-7-1)^2 + (4- (-8))^2 )

C= sqrt(64+144) = sqrt(208) = sqrt (16*13) = 4sqrt(13)