PLEASE HELP WITH 19 AND 20, ONLY DESCRIBE THE TRANSFORMATIONS. I CAN GRAPH THEM. PLS HELP

If a and b are the measures of two first quadrant angles and sin a = 4/9 and sin b = 2/5 find sin(a+b).

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?

Identify the number as a rational or irrational. explain. 127