How many lines of symmetry does an isosceles triangle have

The mean temperature for the first 4 days in january was 7°c. the mean temperature for the first 5 days in january was 5°c. what was the temperature on the 5th day?

How do i make someone brainliest? (if you answer me, i might be able to make you brainliest! )

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?