You may have already tried this, to experiment, but what happens when you comment out the lines with the red underlines? Does the code run?
Of course you have to make adjusts to the x, y positions for the remaining elements so you can see them in the smaller default window size:
//size (500, 400); // b/c of red underline, this line commented out to see if code runs
ellipse(50, 50, 100, 50); // adjusted x, y to be able to see in smaller sketch window
rect(50, 50, 100, 50);
rect(75, 75, 150, 100);
rect(85, 85, 200, 150);
//rect(350, 300, 250,200); // b/c of red underline, this line commented out to see if code runs