All ACT Math Resources
Example Question #1 : Circles
In the figure below, and are radii of the circle. If the radius of the circle is 8 units, how long, in units, is chord ?
The radii and the chord form right triangle . Use the Pythagorean Theorem to find the length of .
Example Question #2 : Chords
A circle has a maximum chord length of inches. What is its radius in inches?
Keep in mind that the largest possible chord of a circle is its diameter.
This means that the diameter of the circle is inches, which means an -inch radius.
Remember that ,
Example Question #2 : Circles
In the circle with center A, shown below, the length of radius is 4 mm. What is the length of chord ?
In order to solve this question, we need to notice that the radii of the circle and chord form a right triangle with as the hypotenuse. We can use the Pythagorean theorem to find chord .