A wire of resistance 6 Ω is cut into three equal pieces, which are joined to form a triangle. The equivalent resistance between any two corners of the triangle is

4/3 Ω

$\text{Here each side will have a resistance of }2\Omega$

$\text{Here two sides are in series and the third one is in parallel with it}$

$R_{eq} = \frac{2\times 4}{2+4} = \frac{4}{3}\Omega$