dc.drawRectangle() radius and other objects...?

hmmm radius for circle inside square?

r = square_width / 2 (actually square_width should be equal to square_height)

drawArc(x, y, r, attr, degreeStart, degreeEnd)

vertical line just a line where start point and end point have the same X coordinate

horizontal line - the same Y coordinate 

drawLine(x1, y1, x2, y2)

in case you want to make pointing cross inside square with circle just draw to lines where vertical x = x_square_left corner + r and horizontal y = square_top_corner +r 

WatchFace with the aim cross? hmmm interesting

NO

rounded squares - edges...

dc.setColor(Gfx.COLOR_WHITE, Gfx.COLOR_TRANSPARENT);
dc.setPenWidth(1.5);
dc.drawRectangle(40, 80, 125, 100);

Radius xxx???

    function drawAimCross(dc){
    	var squareCornerX = 120;
    	var squareCornerY = 180;
    	var squareWidth = 41;
    	var squareHeight = 41;
    	
    	dc.setColor(Gfx.COLOR_WHITE, Gfx.COLOR_TRANSPARENT);
		dc.setPenWidth(1);
		dc.drawRectangle(squareCornerX, squareCornerY, squareWidth, squareHeight);
		
		//calculating circle center
		var circleX = squareCornerX + squareWidth / 2;
		var circleY = squareCornerY + squareHeight /2;
		
		//calculating circle radius (actually as we have squareWidth and squareHeight it is not square rather rectangle, but who cares
		var circleR = squareWidth / 2;
		
		//draw the circle
		dc.setColor(Gfx.COLOR_RED, Gfx.COLOR_TRANSPARENT);
		dc.setPenWidth(2);
		
		dc.drawCircle(circleX, circleY, circleR);
		
		//draw aim cross (center of circle is also center of the aim cross)
		dc.drawLine(squareCornerX, circleY, squareCornerX + squareWidth, circleY);
		dc.drawLine(circleX, squareCornerY, circleX, squareCornerY + squareHeight);
    }

Thank you for the target, but I'm trying to create rounded corners of squares.

https://daydreamintoreality.com/wp-content/uploads/2019/08/Make-a-rounded-square-cricut-6m-962x1024.jpg

    function drawAimCross(dc){
    	var squareCornerX = 120;
    	var squareCornerY = 180;
    	var squareWidth = 41;
    	var squareHeight = 41;
    	
    	var roundedRectangleX = 120;
    	var roundedRectangleY = 10;
    	
    	dc.setColor(Gfx.COLOR_WHITE, Gfx.COLOR_TRANSPARENT);
		dc.setPenWidth(1);
		dc.drawRectangle(squareCornerX, squareCornerY, squareWidth, squareHeight);
		
		//rounded rectangle
		dc.setColor(Gfx.COLOR_GREEN, Gfx.COLOR_TRANSPARENT);
		dc.setPenWidth(2);
		//calculate rounded rectangle radius
		var rrr = (squareWidth + squareHeight) / 20; // 20 is optional, but should be nice
		dc.drawRoundedRectangle(roundedRectangleX, roundedRectangleY, squareWidth, squareHeight, rrr);
		
		
		//calculating circle center
		var circleX = squareCornerX + squareWidth / 2;
		var circleY = squareCornerY + squareHeight /2;
		
		//calculating circle radius (actually as we have squareWidth and squareHeight it is not square rather rectangle, but who cares
		var circleR = squareWidth / 2;
		
		//draw the circle
		dc.setColor(Gfx.COLOR_RED, Gfx.COLOR_TRANSPARENT);
		dc.setPenWidth(2);
		
		dc.drawCircle(circleX, circleY, circleR);
		
		//draw aim cross (center of circle is also center of the aim cross)
		dc.drawLine(squareCornerX, circleY, squareCornerX + squareWidth, circleY);
		dc.drawLine(circleX, squareCornerY, circleX, squareCornerY + squareHeight);
    }

Just check below 

//rounded rectangle comment

Thank you very much for your help, but I still want to ask if it is possible to create a circle or cubes with animation so that they circulate?

Yes, you can animate. You just need to change the size/shape/position over time and update the display as you go.

Please help me i want to make an animation on the dial where there will be a square around the whole dial which will replace the seconds.

This link is broken: developer.garmin.com/.../WatchUi.html

Thank You