Question

$(1,-1),$ $(-\frac{1}{2},\frac{1}{2})$ and $(1,2)$ are the vertices of a/an__________ triangle.

• A. equilateral
• B. isosceles
• C. right angled
• D. scalene

Answer 1

Answer: (B)

isosceles

Distance between the points $(1,-1),(\frac{-1}{2},\frac{1}{2})$ is $\sqrt{{\left(\frac{3}{2}\right)}^2+{\left(\frac{-3}{2}\right)}^2}=\frac{3}{\sqrt{2}}$

Similarly, distance between the points $\left(\frac{-1}{2}\right),(1,2)$ is $\frac{3}{\sqrt{2}}$

Similarly, distance between the points $(1,-1),(1,2)$ is $3$

As two sides are equal, it is an isosceles triangle.