I need help with these:

Question

Suppose triangleABC ~ triangleJKL with BC = 28, JK = 12, and KL = 42. Find the perimeter of triangleABC if the perimeter of triangleJKL is 72.

&

Find the scale factor of triangleDEF to triangleXYZ if triangleDEF ~ triangleXYZ, DE=10, XZ=20, and XY=45.

If I can help on these two, I can do the rest of my worksheet. Step by step would help a lot!

BC is to KL as perimeterABC is to 72

28/12=P/72
solve for P.

2)
De/XY= scale factor
10/45= scale factor