arrow
arrow
arrow
Two circles, centred at P and Q intersect at two points C and D. AB is tangent to the two circles at A and B. If ∠ADB = 68°, then ∠ACB = ____.
Question

Two circles, centred at P and Q intersect at two points C and D. AB is tangent to the two circles at A and B. If ∠ADB = 68°, then ∠ACB = ____.

A.

132°

B.

112°

C.

124°

D.

102°

Correct option is B

Given:
Two circles intersect at points C and D.
AB is a common tangent to the two circles at points A and B.
∠ADB=68∘\angle ADB = 68^\circADB=680    
Concept Used: 
Alternate segment theorem:
By alternate segment theorem 
BCE=BACACD=ABC\angle BCE = \angle BAC \\\angle ACD = \angle ABC 
Solution: 
joining C and D point , now,
By Alternate Segment theorem, 
BAC=CDAandABC=BDC\angle BAC = \angle CDA \\ \text{and} \quad \angle ABC = \angle BDC 
As we know, ADB=680 
∠ADC+∠BDC=∠ADB=68∘\angle ADC + \angle BDC = \angle ADB = 68^\circADC+BDC=ADB=68  
Now, in ABC\triangle ABC 

BAC+ABC+ACB=18068+ACB=180ACB=18068=112\angle BAC + \angle ABC + \angle ACB = 180^\circ \\ 68^\circ + \angle ACB = 180^\circ \\\bf\angle ACB = 180^\circ - 68^\circ = 112^\circ 

Alternate Mehtod:  
ADC+ACB=1800So,ACB=1800680=1120\angle ADC + \angle ACB = 180^0 \\\text{So,} \angle ACB = 180^0 - 68^0 = 112^0​​​​

Free Tests

Free
Must Attempt

SSC GD PYP (Held on 4 Feb 2025 S1)

languageIcon English
  • pdpQsnIcon80 Questions
  • pdpsheetsIcon160 Marks
  • timerIcon60 Mins
languageIcon English
Free
Must Attempt

Hindi Section Test 1

languageIcon English
  • pdpQsnIcon20 Questions
  • pdpsheetsIcon40 Marks
  • timerIcon12 Mins
languageIcon English
Free
Must Attempt

SSC GD Constable Full Mock Test 1

languageIcon English
  • pdpQsnIcon80 Questions
  • pdpsheetsIcon160 Marks
  • timerIcon60 Mins
languageIcon English

Similar Questions

test-prime-package

Access ‘SSC CGL’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
354k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow