Build the defining features
Join segments to build triangles, rectangles and squares.
Explore this lesson →5 practice questions · Optional read aloud · Thinking pad
Let’s understand the idea.
- Choose a shape and think about its defining sides and corners.
- Join the outside points with straight segments and close the boundary.
- A diagonal inside the shape is not an extra outside side.
Something to notice
Ask the learner to build or draw a shape without supplied points, then explain which features make it that shape. The API verifies the specified segment construction, not freehand or physical work.
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 1 · 1.G · 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.