- [tex]\rm{AC\:=\:19.7}[/tex]
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Solution
Diameter is perpendicular to the chord if it bisects the chord.
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Pythagorean theorem
leg² + leg² = hypotenuse²
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[tex]\rm{AW\:=\:22\:-\:4\:=\:18}[/tex]
[tex]\rm{CW\:=\:\frac{1}{2}\:CD\:=\:\frac{1}{2}\:×\:16\:=\:8}[/tex]
[tex]\rm{18^2\:+\:8^2\:=\:AC^2}[/tex]
[tex]\rm{324\:+\:64\:=\:AC^2}[/tex]
[tex]\rm{388\:=\:AC^2}[/tex]
[tex]\boxed{ \rm{AC\:=\:\sqrt{388}\:≈\:19.7}}[/tex]
