Nick Jonas Sings 'Check That Shape' on 'Sesame Street' - Watch!

Nick Jonas strikes a pose with Sesame Street characters during his appearance on the show, which will air on Saturday (May 21).

The 23-year-old “Chains” singer performed a passionate original song about geometric shapes for the show.

Nick helped Bert, Cookie Monster, The Count and viewers at home “check that shape” as he taught them how to count the sides of a shape to know what it is.

“It’s a shape that is so fine. Yeah, that shape drives me out of my mind,” Nick sang.

Check out the video below!