AP EAMCET202021 Sep 2020Evening ShiftMathematicsVector AlgebraActual
Given, ( A B C ) such that (A ) is (2 i - j + k , B ) is ( i -3 j -5 k ) and (C ) is (3 i -4 j -4 k ), then ( A B C ) is
Options
- AAn equilateral triangle
- BA right-angled triangle
- CAn isosceles triangle
- DA scalene triangle
Correct answer
B. A right-angled triangle
Step-by-step solution
Vertices of ( A B C ) are given as (A ) is (2 i - j + k ) (B ) is ( i -3 j -5 k ) and (C ) is (3 i -4 j -4 k ) ( A B =- i -2 j -6 k , B C =2 i - j + k ) and ( C A = i -3 j -5 k ) ( gathered | A B |= 1+4+36 = 41 | B C |= 4+1+1 = 6 gathered ) and (| C A |= 1+9+25 = 35 ) ( | A B |^2=| B C |^2+| C A |^2 ) ( A B C ) is an right-angled triangle. Hence, option (b) is correct.