For a regular polygon with n sides, interior angle
= [(n-2) × 180°]/n
So, interior angle of this regular heptagon shape
= [(7 - 2) × 180°]/7
= (5 × 180°)/7
= 900°/7
= (900/7)°
= 128.571° [approximately]
I'll help on 12. You know that 5*5 is 25. therefore what times 5 equals 20?
Answer:

Step-by-step explanation:
We have been given that at midnight, the temperature was
. At noon, the temperature was
.
Since our temperature has increased to 23 degree Fahrenheit from -8 degree Fahrenheit, we can represent this increase in temperature as:

Therefore, the expression
represents the increase in temperature.
we can find the answer to this problem by thinking about it logically for a minute:
we know that she assigned "x" homework problems on Monday, so,
x=Monday
we also know that she assigned 13 more problems on Tuesday, so,
13=Tuesday
over the course of the two days she assigned a total of 23 homework problems.
to get the answer of how many problems she assigned on Monday, we have to do the total number of problems she assigned(23) minus the number of problems we know she assigned on Tuesday(13), so,
23-13=10
she assigned 10 problems on Monday.