How do you do application of linear equations

What is the area of triangle abc if a = 8, b = 11, and c = 15?

If g(x) is an odd function, which function must be an even function?

The line plot below represents the number of letters written to overseas pen pals by the students at the waverly middle school.each x represents 10 students. how many students wrote more than 6 and fewer than 20 letters. a.250 b.240 c.230 d.220