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45 votes
Properties of chords. leave answer in simplest form. DONT TAKE FOREVER TO ANSWER

Properties of chords. leave answer in simplest form. DONT TAKE FOREVER TO ANSWER-example-1
User Anjan Bharadwaj
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1 Answer

12 votes
12 votes

Let's put more details in the figure to better understand the problem:

To be able to determine DC, let's treat this as two similar triangles and apply ratio and proportion.

We get,


\text{ }\frac{\text{ AB}}{\text{ OB}}\text{ = }\frac{\text{ EF}}{\text{ OE}}
(18)/(12)\text{ = }\frac{x}{\text{ 10}}
\frac{18\text{ x 10}}{12}\text{ = }x
(180)/(12)\text{ = }x
15\text{ = }x
\text{ FE = 15}

If a diameter or radius is perpendicular to a chord, then it bisects the chord and its arc. Therefore, we can say that FE = ED.

Determining the length of FD, we get:


\text{ FE + ED = FD}
\text{ FE + FE = FD}
\text{ 15 + 15 = FD}
\text{ FD = 30}

Therefore, FD = 30

Properties of chords. leave answer in simplest form. DONT TAKE FOREVER TO ANSWER-example-1
User Jojay
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3.4k points