Statement I is true because the perimeter of any triangle is indeed greater than the sum of the lengths of its medians. This is a well-established property in geometry, and it holds for all types of triangles.
Statement II is also true. It is known as a triangle inequality for a point inside the triangle: if D is any point on side BC, then the sum of the distances from A to D, B to D, and C to D is always greater than the length of any side of the triangle. This inequality holds true for all triangles and is one of the fundamental results in geometry