Home
Class 12
MATHS
Given a right triangle with /A =90^@. Le...

Given a right triangle with `/_A =90^@`. Let M be the mid-point of BC. If the radii of the triangle `ABM and ACM` are `r_1 and r_2` then find the range of `r_1/r_2`.

Text Solution

Verified by Experts

In the figure, D is mid-point of BC. From the geometry, `AD = BD = CD = a//2`
In `DeltaABD, r_(1) = (Delta_(1))/(s_(1))`
`rArr r_(1) = ((1)/(2) ((a)/(2))h)/(((a)/(2) + (a)/(2) c)/(2))`
`rArr r_(1) = (ah)/(2(a + c))`

In `Delta ACD, r_(2) = (Delta_(2))/(s_(2))`
`rArr r_(2) = ((1)/(2) ((a)/(2))h)/(((a)/(2) + (a)/(2) + b)/(2))`
`rArr r_(2) = (ah)/(2(a + b))`
`rArr (r_(1))/(r_(2)) = (a + b)/(a + c)`
`= (2R sin A + 2 R sin B)/(2R sin A + 2R sin C)`
`= (1 + sin B)/(1 + sin C) " " ("as " A = 90^(@))`
`= (1+ sin B)/(1+ cos B) " " ("as " C = 90^(@) - B)`
When B aproaches to `90^(@), (r_(1))/(r_(2))` approaches to 2
When B approaches to `0^(@), (r_(1))/(r_(2))` approaches to `(1)/(2)`
`:. (r_(1))/(r_(2)) in ((1)/(2), 2)`
Promotional Banner

Topper's Solved these Questions

  • PROPERTIES AND SOLUTIONS OF TRIANGLE

    CENGAGE PUBLICATION|Exercise Concept application exercise 5.1|12 Videos
  • PROPERTIES AND SOLUTIONS OF TRIANGLE

    CENGAGE PUBLICATION|Exercise Concept application exercise 5.2|8 Videos
  • PROPERTIES AND SOLUTIONS OF TRIANGLE

    CENGAGE PUBLICATION|Exercise Archives (Numerical Value Type)|3 Videos
  • PROGRESSION AND SERIES

    CENGAGE PUBLICATION|Exercise ARCHIVES (NUMERICAL VALUE TYPE )|8 Videos
  • RELATIONS AND FUNCTIONS

    CENGAGE PUBLICATION|Exercise All Questions|1119 Videos

Similar Questions

Explore conceptually related problems

Let A B C be a triangle with /_B=90^0 . Let AD be the bisector of /_A with D on BC. Suppose AC=6cm and the area of the triangle ADC is 10c m^2dot Find the length of BD.

If the sides of a triangle are in the ratio 3 : 7 : 8 , then find R : r

In a triangle ABC, angleC=90^@, r and R are the inradius and circumradius of the triangle ABC respectively, then 2(r+R) is equal to

Let p,q,r be the altitudes of a triangle with area s and perimeter 2t. Then the value of 1/p+1/q+1/r is

In a right -angled triangle, prove that r+2R=S.

In triangle ABC, if r_(1) = 2r_(2) = 3r_(3) , then b : c is equal to

In a triangle ABC, angleC=90^(@) , r and R are the in-radius and circum-radius of the triangle ABC respectively, then 2(r+R) is eqaul to

In triangle ABC, a=5,b=4,c=3. G is the centroid of triangle. If R_1 be the circumradius of triangle GAB, then the value of 325/R_1^2 must be

Let ABC be an isosceles triangle with base BC. If r is the radius of the circle inscribsed in DeltaABC and r_(1) is the radius of the circle ecribed opposite to the angle A, then the product r_(1) r can be equal to (where R is the radius of the circumcircle of DeltaABC )

CENGAGE PUBLICATION-PROPERTIES AND SOLUTIONS OF TRIANGLE-Illustration
  1. Let I be the incetre of ΔABC having inradius r. Al, BI and Ci intersec...

    Text Solution

    |

  2. In A B C , the three bisectors of the angle A, B and C are extended t...

    Text Solution

    |

  3. Given a right triangle with /A =90^@. Let M be the mid-point of BC. If...

    Text Solution

    |

  4. Prove that the distance between the circumcenter and the incenter of ...

    Text Solution

    |

  5. Prove that acosA+bcosB+ccosClt=sdot

    Text Solution

    |

  6. about to only mathematics

    Text Solution

    |

  7. If in A B C , the distances of the vertices from the orthocentre are ...

    Text Solution

    |

  8. ABC is an acute angled triangle with circumcenter O and orthocentre H....

    Text Solution

    |

  9. In a acute angled triangle ABC, proint D, E and F are the feet of the ...

    Text Solution

    |

  10. Prove that he distance between the circum-centre and the ortho-centre ...

    Text Solution

    |

  11. Let ABC be an acute angled triangle whose orthocentre is at H. If a...

    Text Solution

    |

  12. In A B C , let L ,M ,N be the feet of the altitudes. The prove that s...

    Text Solution

    |

  13. The lengths of the medians through acute angles of a right-angled tr...

    Text Solution

    |

  14. Two medians drawn from the acute angles of a right angled triangle ...

    Text Solution

    |

  15. Prove that r1+r2+r3-r=4R

    Text Solution

    |

  16. If r1 =r2+r3+r, prove that the triangle is right angled.

    Text Solution

    |

  17. Prove that (r(1+r2))/1=2R

    Text Solution

    |

  18. Prove that (r+r1)tan((B-C)/2)+(r+r2)tan((C-A)/2)+(r+r3)tan((A-B)/2)=0

    Text Solution

    |

  19. If the distance between incenter and one of the excenter of an equi...

    Text Solution

    |

  20. If I1, I2, I3 are the centers of escribed circles of triangle A B C ,...

    Text Solution

    |