A sketch is useful as a communication tool. By expressing ideas using sketches, we can explain the information we want to convey to others in an easy-to-understand way. In general, learning sketches is done by experienced teacher feedback. If we can do this approach with technology, we can expect to provide sketch education opportunities to many people. In our system, utilizing the fact that cube sketch can be evaluated by perspective, we recognize and evaluate the sketch of the learner's cube and educate sketch acquisition by feeding back the mistake. The developed system is evaluated by testing whether the handwritten cube can be recognized and whether we can point out the mistakes of the learner's cube correctly.