Someone pleaseee help me

When y’all answer can y’all explain too !

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?

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?