J. I Uhhulll. Ir! Step 1: Poke a small hole in a piece of cardboard with a pen or sharp pencil. Hold the cardboard in the sunlight and note the circular image that is cast on a convenient screen of any kind. This is an image of the Sun. Unless you're holding the card too close, note that the solar image size does not depend on the size of the hole in the cardbon (pinhole), but only on its distance om the pinhole to the screen. The greater the distance between the image and the cardboard, the larger the sunbail. Step 2: Position the cardboard so the image exactly covers a dime, or something that can be accurately measured. Carefully measure the distance to the small hole in the cardboard. Record your measurements as a ratio: diameter of dime _ distance from dime to pinhole Because this is the same ratio as the diameter of the Sun to its distance, then diameter of dime _ diameter of sun distance from dime to pinhole distance from sun to pinhole