Home
Class 12
MATHS
Find the angles of /\ABC whose vertices ...

Find the angles of `/_\ABC` whose vertices are `A(-1,3,2), B(2,3,5) and C(3,5,-2)`.

A

`45^@`

B

`60^@`

C

`90^@`

D

`30^@`

Text Solution

Verified by Experts

The correct Answer is:
C
Now DR's of AB = (2+1,3-3,5-2) = (3,0,3) and AC = (3+1,5-3,-2-2) = (4,2,-4)
`thereforecosA=(3xx4+0xx2+3xx-4)/(sqrt(3^2+0+3^2)sqrt(4^2+2^2+(-4)^2))=(12-12)/(sqrt(36)sqrt(36))=0`
`rArr" "angleA=90^@`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • THREE DIMENSIONAL GEOMETRY

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise MHT CET Corner|3 Videos

  • THREE DIMENSIONAL GEOMETRY

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise MHT CET Corner|3 Videos

  • STRAIGHT LINE

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise EXERCISE 2(MISCELLANEOUS PROBLEMS)|30 Videos

  • TRIGONOMETRIC FUNCTIONS

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise EXERCISE 2 (MISCELLANEOUS PROBLEMS)|26 Videos

Similar Questions

Explore conceptually related problems

Using vectors,find the area of the /_ABC, whose vertices are A(1,2,3),B(2,-1,4) and C(4,5,-1)

Find the angles of a triangle whose verties are A(3,2,1), B(35,2) and C(5,-2,3) .

Find the angles of a triangle whose vertices are A(0,-1,-2),B(3,1,4) and C(5,7,1)

Using vectors, find the area of Delta ABC whose vertices are (i) A(1,1,2),B(2,3,5) and C(1,5,5) (ii) A(1,2,3),B(2,-1,4) and C(4,5,-1) (iii) A(3,-1,2),B(1,-1,-3) and C(4,-3,1) (iv) A ( 1,-1,2),B(2,1,-1) and C(3,-1,2).

Find the area of the triangle whose vertices are A(1,2,3) , B(2,3,1) and C(3,1,2)

Using integration, find the area of the triangle ABC whose vertices are A(-1,1), B(0,5) and C(3,2) .

Find the angles of a triangle whose vertices are A(0,-1,-2),B(3,1,4)and C(5,7,1)

Find the area of Delta ABC whose vertices are : (i) A(1, 2), B (-2, 3) and C(-3, -4) (ii) A(-5, 7), B(-4, -5) and C(4, 5) (iii) A(3, 8), B(-4, 2) and C(5, -1) (iv) A(10, -6), B(2, 5) and C(-1, 3)

Find the area of triangle ABC whose vertices are A(-3, -5), B(5,2) and C(-9,-3).

Find the area of Delta ABC whose vertices are A(2, 7), B(3, -1) and C(-5, 6).

Home
Profile