Two long, straight wires, each with a current of $12.0 \mathrm{A},$ are placed on two corners of an equilateral triangle with sides of length $2.50 \mathrm{cm}$ as shown. Both of the wires have a current into the page.
(a) What is the magnetic field at the third corner of the triangle? (b) Another wire is placed at the third corner, parallel to the other two wires. In which direction should current flow in the third wire so that the force on it is in the $+y$ -direction?