Home
Class 12
MATHS
If in a triangle ABC ,(b+c)/11=(c+a)/12=...

If in a triangle ABC ,`(b+c)/11=(c+a)/12=(a+b)/13` then cosA is equal to

A

`1/5`

B

`5/7`

C

`19/35`

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM

    OBJECTIVE RD SHARMA|Exercise Chapter Test|55 Videos

  • PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM

    OBJECTIVE RD SHARMA|Exercise Section II - Assertion Reason Type|13 Videos

  • PLANE AND STRAIGHT LINE IN SPACE

    OBJECTIVE RD SHARMA|Exercise Chapter Test|31 Videos

  • REAL FUNCTIONS

    OBJECTIVE RD SHARMA|Exercise Chapter Test|60 Videos

Similar Questions

Explore conceptually related problems

With usual notations, if in a triangle ABC (b+c)/(11) = (c+a)/(12) = (a+b)/(13) , then cos A : cos B : cos C is :

In triangleABC , If (b+c)/(11)=(c+a)/(12)=(a+b)/(13) , then cosC=

With usual notion,if in triangle ABC ,(b+c)/(11)=(c+a)/(12)=(a+b)/(13), then prove that (cos A)/(7)=(cos B)/(19)=(cos C)/(25)

With usual notations,if in a triangle ABC(b+c)/(11)=(c+a)/(12)=(a+b)/(13), then prove that: (cos A)/(7)=(cos B)/(19)=(cos C)/(25)

In a triangle ABC, if a = 2, b = 3 and c=4 , then cos A is equal to

With usual notatins, if in a Delta ABC,(b+c)/(11)=(c+a)/(12) =(a+b)/(13), then prove that (cos A)/(7) =(cos B)/(19) =(cos C)/(25).

In triangle ABC ,if (b+c)^(2)=a^(2)+16Delta, then tan A is equal to

In a triangle ABC cos A = 7/8 , cos B = 11/16 .then , cos C is equal to

OBJECTIVE RD SHARMA-PROPERTIES OF TRIANGLES AND CIRCLES CONNECTED WITH THEM-Exercise
  1. In a triangle ABC ,cos A + cos B + cos C =3/2, then the triangle ,is

    Text Solution

    |

  2. In any triangle ABC, if cosA cos B + sin A sin B sinC =1 then prove th...

    Text Solution

    |

  3. If in a triangle ABC ,(b+c)/11=(c+a)/12=(a+b)/13 then cosA is equal t...

    Text Solution

    |

  4. If p(1),p(2),p(3) are altitudes of a triangle ABC from the vertices A,...

    Text Solution

    |

  5. If p(1),p(2),p(3) are altitudes of a triangle ABC from the vertices A,...

    Text Solution

    |

  6. P(1), P(2), P(3) are altitudes of a triangle ABC from the vertices A, ...

    Text Solution

    |

  7. If median of the DeltaABC through A is perpendicular to BC, then which...

    Text Solution

    |

  8. In DeltaABC if (sinA)/(sinC)=(sin(A-B))/(sin(B-C)), then a^(2), b^(2)...

    Text Solution

    |

  9. If in a !ABC ,a tan A + btanB =(a + b) tan((A+B)/2) , then

    Text Solution

    |

  10. If in a !ABC , cosA=(sinB)/(2sinC) then the !ABC , is

    Text Solution

    |

  11. If in a triangle ABC,(a^(2)-b^(2))/(a^(2)+b^(2)) then the triangle is

    Text Solution

    |

  12. If in a triangle ABC, b + c = 3a, then tan(B/2)tan(C/2) is equal to

    Text Solution

    |

  13. Let ABC be a triangle such that angle A =45^(@) , angle B =75^(@), the...

    Text Solution

    |

  14. If in a DeltaABC , cos A + 2 cosB+cosC= 2, then a,b, c are in

    Text Solution

    |

  15. If the altitudes of a triangle are in A.P,then the sides of the triang...

    Text Solution

    |

  16. In any !ABC ,the distance of the orthocentre from the vertices A, B,C ...

    Text Solution

    |

  17. If R is the radius of circumscribing circle of a regular polygon of n-...

    Text Solution

    |

  18. If r is the radius of inscribed circle of a regular polygon of n-sides...

    Text Solution

    |

  19. The area of a regular polygon of n sides is (where r is inradius, R is...

    Text Solution

    |

  20. If r,r(1) ,r(2), r(3) have their usual meanings , the value of 1/(r(1)...

    Text Solution

    |