Question

1) In the given figure, AB is a diameter of a circle with centre O

and DO ∥ CB. If ∠BCD = 120°, calculate

a) ∠BAD

b) ∠ABD

c) ∠CBD

d) ∠ADC

Also, show that that ∆AOD is an equilateral triangle


pls also explain it​

Answer 1

Answer:

a.) If ∆ BCD= 120°

So ∆ BOD is also 120° ( vertically opposite angles) As you know that Angle A+B+C = 180° ( Angle sum property of a triangle)

Hence, ∆ BAD = 180°-120°=60°

b.) ∆ BAD= 60°

∆ BCD= 120°

Hence, ∆ ABD = 120+60= 180°

c.) ∆ CBD AND ∆ BOD ARE EQUAL.

d.) ∆ ADC IS A COMPLETE ANGLE ( 360°)

YES, ∆AOD IS AN EQUILATERAL TRIANGLE AS IS EACH SIDE IS OF 60°.

Step-by-step explanation:

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