# M:N:MC:14

Exam

Learn more about this exam.

Skill

Learn more about Additional Topics in Math.

The semicircle above has a radius of *r* inches, and chord is parallel to the diameter If the length of is of the length of what is the distance between the chord and the diameter in terms of *r*?

### Select an Answer

### View Correct Answer

Choice D is correct. This represents the length of the distance between the chord and the diameter, using a radius of the circle to create a triangle, and then the Pythagorean theorem to solve correctly: where *r* represents the radius of the circle and *x *represents the distance between the chord and the diameter.

Choice A is not the correct answer. It does not represent the length of the distance between the chord and the diameter. The student who selects this answer may have tried to use the circumference formula to determine the distance rather than making use of the radius of the circle to create a triangle.

Choice B is not the correct answer. It does not represent the length of the distance between the chord and the diameter. The student who selects this answer may have tried to use the circumference formula to determine the distance rather than making use of the radius of the circle to create a triangle.

Choice C is not the correct answer. It does not represent the length of the distance between the chord and the diameter. The student who selects this answer may have made a triangle within the circle, using a radius to connect the chord and the diameter, but then may have mistaken the triangle for a 45-45-90 triangle and tried to use this relationship to determine the distance.

Students must make use of properties of circles and parallel lines in an abstract setting.