Point C divides the chord AB into segments 12cm and 16cm. Find the diameter of the circle if the distance
Point C divides the chord AB into segments 12cm and 16cm. Find the diameter of the circle if the distance from point C to the center of the circle is 8cm.
Let us determine the length of the chord AB.
AB = AC + BC = 12 + 14 = 28 cm.
Let’s draw the radii OA and OB from the center of the circle. Since ОА = ОВ = R, the triangle AOB is isosceles.
Let’s draw the height OH of the triangle AOB, which will also be the median of the triangle.
Then AH = BH = AB / 2 = 28/2 = 14 cm.
Segment CH = AН – AC = 14 – 12 = 2 cm.
In a right-angled triangle COН, according to the Pythagorean theorem, we determine the length of the leg OH.
OH ^ 2 = OC ^ 2 – CH ^ 2 = 8 ^ 2 – 2 ^ 2 = 64 – 4 = 60.
In a right-angled triangle AOН, by the Pythagorean theorem, we determine the length of the hypotenuse OA.
OA ^ 2 = AH ^ 2 + OH ^ 2 = 196 + 60 = 256.
ОА = R = 16 cm.
Determine the diameter of the circle. D = 2 * R = 2 * 16 = 32 cm.
Answer: The diameter of the circle is 32 cm.