1a) I’m assuming that you’re looking for a rule, so here it is: 3.14x7^2
1b) Expression: Area: 3.14x7^2=153.86
Explanation: So to find the area you multiply Pi, which is commonly expressed as 3.14, and multiply that by the radius squared. That would give you the answer!
Hope you understood my vague explanation :)❦ꨄシ