"The heat engine uses 1.00x10^-2 mol of a diatomic gas as the working substance. Determine the temperatures at the 3 points."

Question

From 1-2, it's an adiabatic process and the constants are (P)(V^(7/5)) or (T)(V^(2/5)). From 2-3, it's an isobaric process with V/T as the constant. And from 3-1, it's an isochoric process with P/T as the constant.

I've found that P1 = 100,000Pa, P2 = 400,000Pa, and P3 = 400,000Pa and V2 = .001L.

I know that for diatomic atoms, you use Eth = d/2nRT, where d = 5.

But I'm absolutely stumped on how to get the missing V1, V3, T1, T2, and T3 variables.

Please help!