Answer: [tex]m\overbrace{ED}[/tex]= 168° and ∠ECD = 168°
Step-by-step explanation:
In the given , we have a circle centered at C , ED is a chord and DF is a tangent touching circle at D, ∠EDF = 84°.
Also, CE = CD = radius
⇒ ∠CED = ∠CDE ---(i) [angles opposite to equal sides of triangle are equal]
Since radius makes a right angle with tangent.
So, ∠CDF = 90°
⇒ ∠CDE =∠CDF - ∠EDF
⇒ ∠CDE= 90° - 84°
⇒ ∠CDE = 6°
From (i) ∠CED =∠CDE = 6°
In ΔCDE
⇒∠CED + ∠CDE + ∠ECD = 180°
⇒ 6°+6°+ ∠ECD = 180°
⇒ 12°+ ∠ECD = 180°
⇒∠ECD = 180° - 12°
⇒∠ECD = 168°
Since , Angle measure of the central angle is equal to the measure of the intercepted arc.
Therefore m∠ECD = [tex]m\overbrace{ED}[/tex]
⇒[tex]m\overbrace{ED}[/tex]= 168°
Hence, [tex]m\overbrace{ED}[/tex]= 168° and ∠ECD = 168°
