UGC NET CS 2007-Dec-Paper-2
January 10, 2025UPPCL AE 2019
January 11, 2025GATE 2018
| Question 7 |
In the figure below, ∠DEC + ∠BFC is equal to
| ∠BCD – ∠BAD | |
| ∠BAD + ∠BCF
| |
| ∠BAD + ∠BCD | |
| ∠CBA + ADC |
Question 7 Explanation:
→ ∠1 = ∠5 + ∠4 ………(i)
According to triangular property:
Angle of exterior = sum of interior angles
→ ∠4 = ∠3 + ∠2 ……….(ii)
By substituting (ii) in (i)
→ ∠1 = ∠5 + ∠3 + ∠2
→ ∠1 = ∠BCD
∠2 = ∠BAD
→ ∠BCD – ∠BAD = ∠1 – ∠2
= ∠5 + ∠3 + ∠2 – ∠2
= ∠ 5 + ∠3
= ∠DEC + ∠BFC
Correct Answer: A
Question 7 Explanation:
→ ∠1 = ∠5 + ∠4 ………(i)
According to triangular property:
Angle of exterior = sum of interior angles
→ ∠4 = ∠3 + ∠2 ……….(ii)
By substituting (ii) in (i)
→ ∠1 = ∠5 + ∠3 + ∠2
→ ∠1 = ∠BCD
∠2 = ∠BAD
→ ∠BCD – ∠BAD = ∠1 – ∠2
= ∠5 + ∠3 + ∠2 – ∠2
= ∠ 5 + ∠3
= ∠DEC + ∠BFC