Home
Class 12
MATHS
In a triangle ABC, If A=B=120^(@) and R=...

In a triangle ABC, If `A=B=120^(@)` and R=8r, then the value of cosC is

A

`7/8`

B

`3/4`

C

`4/5`

D

`3/5`

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • TRIGNOMETRIC FUNCTIONS

    AAKASH INSTITUTE|Exercise Section-C (Objective Type Questions More than one options are correct )|45 Videos

  • TRIGNOMETRIC FUNCTIONS

    AAKASH INSTITUTE|Exercise Section D (Linked Comprehension Type Questions)|24 Videos

  • TRIGNOMETRIC FUNCTIONS

    AAKASH INSTITUTE|Exercise Assignment Section-B (Objective Type Questions (One option is correct))|1 Videos

  • THREE DIMENSIONAL GEOMETRY

    AAKASH INSTITUTE|Exercise ASSIGNMENT SECTION - J|10 Videos

  • VECTOR ALGEBRA

    AAKASH INSTITUTE|Exercise SECTION-J (Aakash Challengers Questions)|5 Videos

Similar Questions

Explore conceptually related problems

In a triangle ABC,r=

In a triangle ABC, A - B =120 ^(@) and R = 8r, then the value of cos C is

In DeltaABC," if " A-B=120^(@) and R=8r , then the value of (1+cosC)/(1-cosC) equals : (All symbols used hav their usual meaning in a triangle)

In a Delta ABC If A-B= 120^(@) ,R=8r then 8cos C=

In triangle ABC, if A-B=120^(@) and R=8r, where R and r have their usual meanings,then cos C equal (a) (3)/(4) (b) (2)/(3)(c)(5)/(6) (d) (7)/(8)

In a triangle ' ABC,r_(-)1

In triangle ABC, if A - B = 120^(2) and R = 8r , where R and r have their usual meaning, then cos C equals

In a triangle ABC, if r_(1)+r_(3)+r=r_(2), then find the value of (sec^(2)A+csc^(2)B-cot^(2)C)

In triangle ABC , right angled at B, if tanA =1/2 , then the value of (sinA(cosC + cosA))/(cosC(sinC - sinA)) is: triangle ABC में B एक समकोण है यदि tanA =1/2 तो (sinA(cosC + cosA)) /(cosC(sinC - sinA)) का मान क्या होगा ?

AAKASH INSTITUTE-TRIGNOMETRIC FUNCTIONS -Section-B (Objective Type Questions One option is correct)
  1. In triangleABC, if a^(2)+b^(2)+c^(2)=ac+ab sqrt(3), then

    Text Solution

    |

  2. In a triangle ABC, ab and c are the sides of the triangle satisfying t...

    Text Solution

    |

  3. In triangleABC, which is not right angled, if p=sinA sinB sinC = and q...

    Text Solution

    |

  4. In triangleABC, if R/r le 2, and a=2, then triangle is equal to (trian...

    Text Solution

    |

  5. In triangleABC, If r(1), r(2), r(3) are exradii opposites to angles A,...

    Text Solution

    |

  6. If in a triangle ABC , 2(cosA)/a+(cosB)/b+2(cosC)/c=a/(bc)+b/(ca), ...

    Text Solution

    |

  7. In triangle ABC if the line joining incenter to the circumcenter is pa...

    Text Solution

    |

  8. With usual notations, if in a triangle ABC (b+c)/(11) = (c+a)/(12) = ...

    Text Solution

    |

  9. Consider a regular polygon of 12 sides each of length one until, then ...

    Text Solution

    |

  10. If the perimeter of a triangle is 6, then its maximum area is

    Text Solution

    |

  11. In a triangle ABC, If A=B=120^(@) and R=8r, then the value of cosC is

    Text Solution

    |

  12. In a triangle ABC, we have acosB+bcosC+ccosA=(a+b+c)/2 where A, B, ...

    Text Solution

    |

  13. A regular pentagons is inscribed in a circle. If A(1) and A(2) represe...

    Text Solution

    |

  14. If a^2 +b^2+c^2 = 8R^2 , then the triangle is

    Text Solution

    |

  15. O is the circumcentre of the triangle ABC and R1,R2,R3 are the radii o...

    Text Solution

    |

  16. In triangleABC, if r(1)=2r(2) = 3r(3), then

    Text Solution

    |

  17. In triangleABC, the expression (b^(2)-c^(2))/(asin(B-C)) + (c^(2)-a^2...

    Text Solution

    |

  18. In a triangle ABC. If triangle^(2) = (a^(2)b^(2)c^(2))/(2(a^(2)+b^(2)+...

    Text Solution

    |

  19. ABCD is a trapezium such that AB and DC are parallel and BC is perpend...

    Text Solution

    |

  20. If the median of triangle ABC through A is perpendicular AB, then the ...

    Text Solution

    |