Question - A converging lens is used to project an image of a slide onto a screen 1000mm from the lens, which has a focal length of 200mm. The image is a square with side 250mm. By means of a scale drawing, determine

a) the distance of the slide from the lens, and

b) the size of the slide.

I am stucked at this question... Wishing for a kind soul to show me the scale drawing which includes steps in drawing it

Thanks in advance and sorry for the trouble..