If the blue radius below is perpendicular to the chord AC which is. 14 units long, what is the length of the segment AB?

Answer:
C. 7 units
Step-by-step explanation:
The given parameters are;
The length of the chord of the circle, [tex]\overline{AC}[/tex] = 14 units
The orientation of the radius and the chord = The radius is perpendicular to the chord
We have in ΔAOC, [tex]\overline{AO}[/tex] = [tex]\overline{OC}[/tex] = The radius of the circle
[tex]\overline{OB}[/tex] ≅ [tex]\overline{OB}[/tex] by reflexive property
The angle at point B = 90° by angle formed by the radius which is perpendiclar to the chord [tex]\overline{AC}[/tex]
ΔAOB and ΔCOB are right triangles (triangles having one 90° angle)
[tex]\overline{AO}[/tex] and [tex]\overline{OC}[/tex] are hypotenuse sides of ΔAOB and ΔCOB respectively and [tex]\overline{OB}[/tex] is a leg to ΔAOB and ΔCOB
Therefore;
ΔAOB ≅ ΔCOB, by Hypotenuse Leg rule of congruency
Therefore;
[tex]\overline{AB}[/tex] ≅ [tex]\overline{BC}[/tex] by Congruent Parts of Congruent Triangles are Congruent, CPCTC
[tex]\overline{AB}[/tex] = [tex]\overline{BC}[/tex] by definition of congruency
[tex]\overline{AC}[/tex] = [tex]\overline{AB}[/tex] + [tex]\overline{BC}[/tex] by segment addition postulate
∴ [tex]\overline{AC}[/tex] = [tex]\overline{AB}[/tex] + [tex]\overline{BC}[/tex] = [tex]\overline{AB}[/tex] + [tex]\overline{AB}[/tex] = 2 × [tex]\overline{AB}[/tex]
∴ [tex]\overline{AB}[/tex] = [tex]\overline{AC}[/tex]/2
[tex]\overline{AB}[/tex] = 14/2 = 7
[tex]\overline{AB}[/tex] = 7 units.