Sides AB and DC of a cyclic quadrilateral ABCD are produced to meet at E and sides AD and BC are produced to meet at F. If ∠ADC = 78° and ∠BEC = 52°, then the measure of ∠AFB is:

This question was previously asked in
SSC CGL 2020 Tier-I Official Paper 1 (Held On : 13 Aug 2021 Shift 1)
View all SSC CGL Papers >
  1. 30°
  2. 28°
  3. 26°
  4. 32°

Answer (Detailed Solution Below)

Option 2 : 28°
vigyan-express
Free
PYST 1: SSC CGL - General Awareness (Held On : 20 April 2022 Shift 2)
3.6 Lakh Users
25 Questions 50 Marks 10 Mins

Detailed Solution

Download Solution PDF

Given:

∠ADC = 78° and ∠BEC = 52°

Concept:

The sum of a pair of opposite angles is 180° of a cyclic quadrilateral. 

Calculation:

F1 Ashish Madhu 19.10.21 D5

Now, In quadrilateral ABCD,

∠ADC + ∠ABC = 180° (Sum of opposite angles are 180°)

⇒ ∠ABC = 180° - 78° = 102° 

∠EBC = 180° - 102° = 78° [Linear Pair]

In ΔBEC,

∠BEC + ∠EBC + ∠BCE = 180° 

⇒ 52° + 78° + ∠BCE = 180° 

⇒ ∠BCE = 180° - 130° = 50°

⇒ ∠BCE = ∠DCF = 50° (Vertically opposite angle)

∠ADE + ∠FDC = 180° [Linear Pair]

⇒ ∠FDC = 180° - ∠ADE = 180° - 78° = 102°

In ΔDCF,

∠FDC + ∠DCF + ∠DFC = 180° 

102 + 50 + ∠DFC = 180° 

∠DFC = 180° - 152° = 28° 

∠DFC = ∠AFB = 28° 

∴ The measure of ∠AFB is 28°.

Latest SSC CGL Updates

Last updated on Jun 13, 2025

-> The SSC CGL Notification 2025 has been released on 9th June 2025 on the official website at ssc.gov.in.

-> The SSC CGL exam registration process is now open and will continue till 4th July 2025, so candidates must fill out the SSC CGL Application Form 2025 before the deadline.

-> This year, the Staff Selection Commission (SSC) has announced approximately 14,582 vacancies for various Group B and C posts across government departments.

->  The SSC CGL Tier 1 exam is scheduled to take place from 13th to 30th August 2025.

->  Aspirants should visit ssc.gov.in 2025 regularly for updates and ensure timely submission of the CGL exam form.

-> Candidates can refer to the CGL syllabus for a better understanding of the exam structure and pattern.

-> The CGL Eligibility is a bachelor’s degree in any discipline.

-> Candidates selected through the SSC CGL exam will receive an attractive salary. Learn more about the SSC CGL Salary Structure.

-> Attempt SSC CGL Free English Mock Test and SSC CGL Current Affairs Mock Test.

-> Candidates should also use the SSC CGL previous year papers for a good revision. 

Get Free Access Now
Hot Links: online teen patti real money teen patti app teen patti online game teen patti palace teen patti pro