This SMARTboard lesson provides practice in measuring acute and obtuse angles. The lesson assumes that students know the difference between an acute, obtuse, and a right angle. This lesson includes an interactive protractor tool that allows you to move the arrow as it measures the angle. Students need to line up the angle on the protractor to measure correctly so it's good practice in using a protractor. Slides are self checking and can easily be used as a teacher directed lesson, a small group activity, or as an independent station.Created with Smart Notebook 11. Great for grades 4-7. MUST have SMART Notebook software to download and use this lesson.