Line segments AB and CD are congruent. Their coordinates are A(-11,-3), B(-2,5), C(7,1) and D(x,9). Find the value of x

Answer 1

AB² = (-11 + 2 )² + (-3 - 5)² = 81 + 64

CD² = (7 - x )² + (1 - 9)² = (7 - x )² + 64

Since AB² = CD², we have 81 = (7 - x )²; solve the equation, we have x = -2 or 16.

Answer 2

Use the distance to determine length of AB.

Use is again to determine value of x.