The diagram shows pentagon ABCDE inscribed in a circle, centre O.
Given AB=BC=CD and angle ABC =132
Calculate the value of
i Angle AEB
ii AED
iii COD
Answers
Answer:
We are given,
ABCDE is a pentagon inscribed in a circle.
AB = BC = CD
∠ABC = 132°
Let’s join points E & B and E & C.
Case (i): Measure of angle AEB
Since in cyclic quadrilateral ABCE, the sum of opposite angles is 180°
∴ ∠AEC + ∠ABC = 180°
⇒ ∠AEC = 180° - 132° = 48°
We have, AB = BC
So, ∠AEB = ∠BEC ….. [equal chords subtends equal angles]
∴ ∠AEB = ∠BEC = ½ * ∠AEC = ½ * 48° = 24°
Thus, the measure of angle AEB = 24°
Case (ii): Measure of angle AED
Since we have, AB = BC = CD
∴ ∠AEB = ∠BEC = ∠CED = 24° …… [from case (i)]
Also, from the figure given, we can say,
∠AED = ∠ AEB + ∠BEC + ∠CED = 24°+ 24°+24° = 72°
Thus, the measure of angle AED = 72°
Case (iii): Measure of angle COD
From the figure, we can see that
CD subtends ∠COD at the centre and ∠CED at the circumference of the circle.
And, we know, that the central angle is twice any inscribed angle subtended by the same chord, so,
∠COD = 2 * ∠CED = 2 * 24° = 48°
Thus, the measure of the angle COD = 48°.
Step-by-step explanation:
here is ur answer ! if u have any doubt in S. CHAND of class 10 book then u can message me on my Instagram ! I'd - @singh_aditya_287
brain on !