Question

The coordinates of the vertices of quadrilateral ABCD are A(6, 7), B(4, 2), C(1, 5), and D(3, 8).
ABCD is reflected across the x-axis to form PQRS.

What is the length of diagonal PR?

Answer 1

Since they are reflected, PR = AC. Find the distance between AC

Answer 2

Using the distance formula?
And that would be my answer?

Answer 3

yes, find the distance from (6,7) to (1,5)

Answer 4

i put the sqrt of -29 in my calculator and it came up as 'domain error'
Help?

Answer 5

how did you get sqrt -29? You can't take the root of a negative

Answer 6

It's undefined. using pythagoras theorem: a^2 +b^2 = c^2, 2^2 + 5^2 = c^2
c^2 = 4 +25 = 29
c= sqrt 29

Answer 7

i put in the equation.
(1-6)^2 + (5-7)^2 then find the square root.

Answer 8

after squaring, it should be positive then

Answer 9

Oh i understand. Thank you!

Answer 10

you're welcome