If A×A i.e., A2=I Then A is said to be involutary matrix
True
Recall the definition of a involutary matrix carefully. For matrix A to be involutary it should be a square matrix first and A \times A should be equal to I. If these two conditions are satisfied only then A is said to be an involutary matrix.
Here since A2 is defined, So A is a square Matrix, And A2 = I is given. So statement is correct.