i need to find the approximate surface area of the moon using this formula

The question is “the diameter of the earths moon is on average 3.8×10(little 8) m. Use the formula A=4xr2 to find the approximate surface area.” And I need to show work. I am attaching a pic of the question as well because I don’t have all the keys in my keyboard that matches the symbols in the formula. Thank you for your help