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Can you help me find BD. under the letter A the number is 25°

Can you help me find BD. under the letter A the number is 25°-example-1
User Hyp
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1 Answer

19 votes
19 votes

arc BD is 25°

Step-by-step explanation:

We would apply the secant-secant theorem:


\begin{gathered} \angle A\text{ =}\frac{large\text{ arc - small arc}}{2} \\ \angle A\text{ =}\frac{arc\text{ CE - arc BD}}{2} \end{gathered}

angle A = ∠A =25°

arc BD =?

arc CE = 100°


\begin{gathered} 25\text{ = }\frac{100-arc\text{ BD}}{2} \\ \text{cross multiply:} \\ 2(25)\text{ = 100 - arc BD} \end{gathered}
\begin{gathered} 50\text{ = 100 - arc BD} \\ \text{subtract 100 from both sides:} \\ 50\text{ - 100 = 100 - 100 - arc BD} \\ -50\text{ = - arc BD} \end{gathered}
\begin{gathered} \text{DIvide both sides by -1:} \\ \frac{-50}{-1\text{ }}=\frac{-arc\text{ BD}}{-1} \\ \text{arc BD = 50}\degree \end{gathered}

User Andrewgu
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