Explain one way to add 3 digit number

Which formula gives the area of a triangle? a=1/2(b+h)

Acarnival sold tickets for $1.50 for adults and $1.00 for students. there were 54 tickets sold for a total of $70.50. write a system of equations to represent the number of adult tickets, x, and the number of student tickets, y. find the solution and explain what it means. i'll you if you me

The vertices of a triangle are a(7,5), b(4,2), c(9,2). what is m