Is this product good for 90 degree angles? For instance, If I want to use it for a square or rectangle shaped kids play area, will it maintain sharp, angular corners since it's flexible and comes as a roll?

Hello, thank you for your question about the EasyFlex No-Dig Black Plastic Landscape edging roll. This edging can be used for 90 degree angles. To accomplish this, we recommend cutting the edging and butting both ends together to form the angle. We hope this helps.