हिंदी

In the Given Figure, O is the Centre of the Circle. If ∠Aob = 140° and ∠Oac = 50°; Find: (I) ∠Acb, (Ii) ∠Obc, (Iii) ∠Oab, (Iv) ∠Cba. - Mathematics

Advertisements
Advertisements

प्रश्न

In the given figure, O is the centre of the circle. If ∠AOB = 140° and ∠OAC = 50°; find:

  1. ∠ACB, 
  2. ∠OBC, 
  3. ∠OAB, 
  4. ∠CBA.

योग

उत्तर


Here, `∠ACB = 1/2  "Reflex"  (∠AOB)`

= `1/2 (360^circ - 140^circ)`

= 110°

(Angle at the centre is double the angle at the circumference subtended by the same chord)

Now, OA = OB (Radii of same circle)

∴ ∠OBA = ∠OAB

= `(180^circ - 140^circ)/2`

= 20°

∴  ∠CAB = 50° – 20° = 30°

ΔCAB,

∠CBA = 180° – 110° – 30° = 40°

∴  ∠OBC = ∠CBA + ∠OBA

= 40° + 20°

= 60°

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 17: Circles - Exercise 17 (A) [पृष्ठ २५८]

APPEARS IN

सेलिना Mathematics [English] Class 10 ICSE
अध्याय 17 Circles
Exercise 17 (A) | Q 8 | पृष्ठ २५८
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×