Draw the turn
Use turns, rays and a degree tool to understand angle openings.
Explore this lesson →6 practice questions · Optional read aloud · Thinking pad
Let’s understand the idea.
- The hinge becomes the vertex: the point where two rays meet. Rays show directions, even beyond the drawn arms.
- One degree is one of 360 equal intervals in a full turn. Changing arm lengths or rotating the whole picture does not change an opening.
- Align a protractor at its center and starting zero. Adjacent angle parts add to their whole opening.
Something to notice
Ask the learner to explain what one degree measures, use a physical protractor on a rotated angle and sketch a fresh angle on paper. Ask why changing arm length preserves the angle and how adjacent parts determine an unknown. Digital practice records constrained tool use; physical placement, independent explanation and fresh transfer need separate parent or teacher observation.
Try it. Change it. Explain it.
Open the lesson to use its pictures and controls. In How it works, connect the picture to the idea. In Play & discover, change the quantities and notice what stays the same. In Your turn, answer questions and use the explanation to check your reasoning.
You can ask for help, draw on the thinking pad, or listen to the question and answer options. Progress distinguishes independent work from work completed with help.
Let’s try it →Curriculum connection
Grade 4 · 4.MD · US Common Core
This lesson is mapped to these standards. A completed activity is practice evidence, not a claim of mastery. Content is checked against the linked official standards and its mathematical models are tested.