Questions: En la figura, AB=6 cm, OC=9 cm y OB=3 cm. ¿cuánto mide CD?
Transcript text: En la figura, $A B=6 \mathrm{~cm}, O C=9 \mathrm{~cm}$ y $O B=3 \mathrm{~cm}$. ¿cuánto mide $C D$ ?
Solution
Solution Steps
Step 1: Identify Given Information
We are given the following measurements:
\( AB = 6 \) cm
\( OC = 9 \) cm
\( OB = 3 \) cm
Step 2: Understand the Relationship
The figure shows two intersecting lines \( L_1 \) and \( L_2 \) with point \( O \) as the intersection. We need to find the length of \( CD \).
Step 3: Apply the Intersecting Chords Theorem
The Intersecting Chords Theorem states that if two chords intersect each other inside a circle, the products of the lengths of the segments of each chord are equal. Therefore, we have:
\[ AO \cdot OB = CO \cdot OD \]
Step 4: Calculate Segment Lengths
From the given information:
\( AB = 6 \) cm, so \( AO + OB = 6 \) cm
\( OB = 3 \) cm, so \( AO = 6 - 3 = 3 \) cm
Step 5: Set Up the Equation
Using the Intersecting Chords Theorem:
\[ AO \cdot OB = CO \cdot OD \]
\[ 3 \cdot 3 = 9 \cdot OD \]
Step 6: Solve for \( OD \)
\[ 9 = 9 \cdot OD \]
\[ OD = 1 \) cm
Step 7: Calculate \( CD \)
Since \( CD = CO + OD \):
\[ CD = 9 + 1 = 10 \) cm