https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-angle-introduction/v/acute-right-and-obtuse-angles 2021-06-30T20:49:30Z Acute, right, & obtuse angles Acute angles measure less than 90 degrees.  Right angles measure 90 degrees.  Obtuse angles measure more than 90 degrees.  Learn about angles types and see examples of each. Sal Khan video https://cdn.kastatic.org/googleusercontent/0TrIIisE8BxVp_Bs5Co3G8RXtYcnmx9zu5pR2My5GUcj1JjSm5_G6kkQ4ZMUk0Ln1ry1Q5I7HXnYXTX1BGCdUOnJ Acute, right, & obtuse angles Acute angles measure less than 90 degrees.  Right angles measure 90 degrees.  Obtuse angles measure more than 90 degrees.  Learn about angles types and see examples of each. https://cdn.kastatic.org/ka-youtube-converted/ALhv3Rlydig.mp4/ALhv3Rlydig.mp4 332 Types of angles https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-angle-introduction/e/angle_types 2025-05-27T10:20:27.404259006Z Angle types Determine if an angle is acute, right, or obtuse.  A protractor is provided. Ben Alpert exercise https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-angle-introduction/v/recognizing-angles-examples 2021-06-30T20:49:26Z Recognizing angles Sal identifies acute, obtuse, and right angles in diagrams and pictures. Sal Khan video https://cdn.kastatic.org/googleusercontent/TSOfNlrgBlkSftUPPOoLCmGhIzgd2iNRa8PM7SrelbRsiDTlUhwf-_BJ7ZspSr6-MZhuguc9oZ4TU92ut_4syhM Recognizing angles Sal identifies acute, obtuse, and right angles in diagrams and pictures. https://cdn.kastatic.org/ka-youtube-converted/B0R3MJOrST0.mp4/B0R3MJOrST0.mp4 135 Types of angles https://www.khanacademy.org/math/cc-fourth-grade-math/plane-figures/imp-angle-introduction/e/recognizing-angles 2025-05-27T12:12:40.926204724Z Recognize angles in figures Determine if angles in shapes and pictures are acute, right, or obtuse. Christopher Wobbles Seymour exercise