Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Geometry

Question:

Two chords AB and CD of a circle with centre O intersect each other at P. If ∠APC = 95° and ∠AOD = 110°, then ∠BOC is:

Options:

60°

55°

70°

65°

Correct Answer:

60°

Explanation:

\(\angle\)AOD = \({110}^\circ\) and \(\angle\)APC = \({95}^\circ\)

Let \(\angle\)AOC and \(\angle\)BOD be x and y respectively.

\(\angle\)DCB = \(\angle\)BOD/2

= \(\frac{y}{2}\)

\(\angle\)ABC = \(\angle\)AOC/2

= \(\frac{x}{2}\)

\(\angle\)APC is the external angle for \(\Delta \)PBC

So, \(\angle\)APC = \(\angle\)PBC + \(\angle\)PCB

= 95 = \(\frac{x}{2}\) + \(\frac{y}{2}\)

= x + y = 190

\(\angle\)AOD + \(\angle\)AOC + \(\angle\)BOC + \(\angle\)BOD = 360  (Complete angle)

= 110 + x + y + \(\angle\)BOC = 360

= 110 + 190 + \(\angle\)BOC = 360

= \(\angle\)BOC = 60

Therefore, \(\angle\)BOC is \({60}^\circ\).