When we estimate pi using a decimal we use?

The border line of the linear inequality 4x + 7y < 5 is dotted true or false?

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

Can someone me with this graph problem by the way i need to know the answers by today since this assignment is due ! !