// Drawing a line of length L from x1, y1 tilted at an angle
   // Using Trigonometry functions

void setup() {
   size(500, 500);
   background(255);
   noLoop();
} // setup()

void draw() {
   // draw a line of length, L starting at 400, 400 of angle 30 degrees
   float L = 250;
   float x1 = 300, y1 = 200;
   float angle = 200;
   
   float x2 = x1 + L * cos(radians(angle));
   float y2 = y1 + L * sin(radians(angle));
   
   line(x1, y1, x2, y2);
} // draw()