Ram, a science student, is trying to find the nature of a mirror he found in the lab. For doing that, he set up an experiment. He kept a candle in front of the mirror and a screen behind the candle. Now he started moving the screen until he got a clear image on the screen. Once the image is obtained, he measures and makes a note of the distances between the mirror, candle, and screen as shown.
Ram can use this mirror as a:
[0.8 mark]