Please help algebra 1 math

Points a, b, and c form a triangle. complete the statements to prove that the sum of the interior angles of triangle abc is 180

The lengths of all sides of a triangle are integers when measured in decimeters. one of the sides has length of 1 dm and another of 3 dm. find the perimeter of the triangle.'

If w = 6 units, x = 3 units, and y = 5 units, what is the surface area of the figure? 168 units2 240 units2 144 units2 96 units2