Question

If the blue radius below is perpendicular to the green chord and the segment
AB is 9 units long, what is the length of the chord?

Answer 1

There's the obvious symmetry ultimately because the radii OA and OB are hypotenuses of congruent right triangles.  We can just eyeball the figure and see AB=BC, at least approximately, so the full chord AC=9+9=18

Answer: A. 18 units

Answer 2

Answer : The correct option is, (A) 18 units.

Step-by-step explanation :

According to the property of a circle, if a line passes through the center of a circle and also perpendicular to a chord of the circle, then the line bisects (or divided into two equal parts) that chord of a circle.

As we are given:

Line segment AB = 9 units

According to the property of a circle,

Line segment AB = Line segment BC = 9 units

So, Line segment BC = 9 units

Thus, the length of the chord AC will be:

Length of the chord AC = Line segment AB + Line segment BC

Length of the chord AC = 9 units + 9 units

Length of the chord AC = 18 units

Therefore, the length of the chord is, 18 units.