O is the centre of the circle and ABC and EDC are rangers to the circle. Find the side of angle BCD. You must give reason in your answer. (4marks)PLZZZZZZ HELP!!
![O is the centre of the circle and ABC and EDC are rangers to the circle Find the side of angle BCD You must give reason in your answer 4marksPLZZZZZZ HELP class=](https://us-static.z-dn.net/files/d15/ded16bf8e2e7352aaf0769443bacd086.png)
Every line from the tangent to the centre is 90°. This is said in the circle theorems.
So angle OBC and ODC are 90°.
angle O is twice the size of angle F. This is another circle theorem.
Therefore angle O is 152°.
The quadrilateral of ODBC would equal to 360°. Which means 90° + 90° + 152° = 332°
360° - 332° = 28°.
The answer is 28°
Answer:
∠BCD = 28°
Step-by-step explanation:
arc BD = 2 x inscribed angle ∠BFD = 2 x 76 = 152
arc BFE = 360 - arc BD = 360 - 152 = 208
tangent-tangent angle ∠BCD = (arc BFE - arc BD)/2 = (208 - 152)/2 = 28