Which statement is true in the following statement?

Question

( A ) In any right-angled triangle, the square of the length of hypotenuse is equal to the sum of the square of the length of the other two sides.
( B ) None of these
( C ) The sum of the lengths of any two sides of a triangle is less than the length of the third side
( D ) The total measure of the three angles of a triangle is greater than 180^{\circ}