A triangle is formed by the vertices (4,1), (1,1) and (3,5). The triangle is:
- Scalene
- Isosceles and right-angled
- Right-angled but not isosceles
- Isosceles but not right-angled
Show answer and solution
Correct answer: A. Scalene
1. Side lengths: (4,1)-(1,1) = 3; (1,1)-(3,5) = √(4+16) = √20; (4,1)-(3,5) = √(1+16) = √17.
2. All three sides differ, so it is not isosceles; check right angle: 9 + 17 = 26 ≠ 20, 9 + 20 = 29 ≠ 17, 17 + 20 = 37 ≠ 9, so no right angle.
3. Hence the triangle is scalene.
_Source: RRB Group D CEN-02/2018 PYQ, Q.94._