1.
If the position vectors of the vertices of a triangle are 2i^−j^+k^2\hat{i} - \hat{j} + \hat{k}, i^−3j^−5k^\hat{i} - 3\hat{j} - 5\hat{k} and 3i^−4j^−4k^3\hat{i} - 4\hat{j} - 4\hat{k}, then the triangle is