Given :- chord AB=chord BC=chord AC, angle BAP = angle CAP.
TO PROVE :- Seg CB =Seg CQ
Answers
Since it is given, chord AB = chord BC = chord AC
∴ ∆ ABC will be an equilateral triangle so ∠CAB = ∠ABC = ∠ACB = 60°
Also given, ∠BAP = ∠CAP = ½ * ∠CAB = 30°
∠ACB + ∠BCQ = 180° [Linear pair]
> 60° + ∠BCQ = 180°
> ∠BCQ = 180° - 60°
> ∠BCQ =120°
Therefore, we can say
∠AQB = ½ * [arcAB – arcCP] = ½ * [120° - 60°] = ½ * 60° = 30°
∠AQB + ∠CBQ + ∠BCQ = 180°
⇒ 30° + angle CBQ + 120° = 180°
⇒ ∠CBQ = 180° - (120° + 30°)
⇒ ∠CBQ = 30°
- Since in ∆CBQ, ∠CBQ = ∠AQB = 30°
∴ ∆CBQ is an isosceles triangle
⇒ seg CB = seg CQ
Step-by-step explanation:
- Given data
AB =BC =CA
So ΔABC is an equilateral triangle.
- We can also write
∠ACB = 60° (All angle of equilateral triangle is 60°)
∠BAC = 60°
- ∠BAP =∠PAC = 30° (Given ∠BAP =∠PAC)
Or
∠BAP =∠PAQ = 30°
- ∠APB = ∠ACB (Both angle made on same side of segment)
So ∠APB = 60°
Now we can write
∠APQ = 180 -∠APB ( by linear pair angle)
∠APQ = 180 - 60
∠APQ = 120°
- From Δ APQ, use triangle angle property rules
∠PAQ +∠APQ +∠PQA = 180°
30° +120° +∠PQA = 180°
On solving
∠PQA = 30° =∠BQA
- We have solved that ∠ACB = 60°, So
∠BCQ = 180 -∠ACB ( by linear pair angle)
∠BCQ = 180 - 60
∠BCQ = 120°
- From Δ BCQ, use triangle angle property rules
∠BCQ +∠CQB +∠QBC = 180°
120° +30° +∠QBC = 180°
On solving
∠QBC = 30°
- Now we can say that Δ BCQ is an isosceles triangle
So
BC = CQ (side opposite to equal angle are equal)