Solution

Collenchyma is simple living tissue with thick non lignified walls that provide support to the growing organs and is present in organ that do not develop very woody.
Angular collenchyma has irregularly arranged cells with thickening at corners where they contact with other cells. Example, Datura, Cucurbita.
Tubular collenchyma exhibit thickening at the regions on wall that cover air spaces and have large intercellular spaces. Example, Helianthus and Althaea.