Proper framing for connecting two deck beams together
A skewed joist hanger is the right solution. The key is be sure that the one you choose is robust enough for the intended use. Simpson Strong-Tie, for example, often make similar hangers in several metal gauges and nailing configurations. 

When in doubt, go with the heavier one (though your application is fairly light-duty).

Strong-Tie skewed hanger product page
Strong-Tie skewed hanger PDF
(Links for reference only.)