Objectives for this lesson:
1.
Given diagrams, models, and real-life examples of solids (pyramids, cone), students will identify and list the properties of solids, including faces, edges, vertices, right and non-right angles, base, height, and cross-sections with at least 80% accuracy.
2.
Using straws, sticks, plasticine, or similar materials, students will construct skeletal and plasticine models of solids (cones, pyramids) by accurately representing their properties in 4 out of 5 models.
3.
During hands-on exploration and group activities, students will show curiosity and cooperation while investigating and describing the properties of solids by actively participating, sharing observations, and handling materials responsibly.
Important terms to remember
Solids
Solids are three-dimensional shapes that have length, width, and height.
Solids are shapes you can hold. They are not flat.
👉 Examples: cube, cylinder, cone, sphere
🧠 Think:
“Solids are shapes with depth.”
Cross Sections
A cross section is the shape you see when a solid is cut straight across.
A cross section is what the shape looks like inside when you slice it.
👉 Example:
Cut a cylinder straight across and you see a circle.
🧠 Think:
“What shape do I see when I cut it?”
Base
The base is the bottom face of a solid.
The base is the part of the solid that sits on the table.
👉 Example:
The base of a cube is a square.
🧠 Think:
“What does it stand on?”
Height
The height is the distance from the base to the top of a solid.
Height tells how tall the solid is.
👉 Example:
How tall a box is from the bottom to the top.
🧠 Think:
“How tall is it?”
Faces
Faces are the flat surfaces of a solid.
Faces are the flat sides you can see and touch.
👉 Example:
A cube has 6 faces.
🧠 Think:
“Flat sides.”
Edges
Edges are the lines where two faces meet.
Edges are the straight lines where flat sides join.
👉 Example:
A cube has 12 edges.
🧠 Think:
“Lines where faces meet.”
Vertices
Vertices are the corners where edges meet.
Vertices are the pointy corners of a solid.
👉 Example:
A cube has 8 vertices.
🧠 Think:
“Corners.”
Right Angles
A right angle is an angle that measures 90 degrees.
A right angle looks like the corner of a book or door.
👉 Example:
Most corners of a box are right angles.
🧠 Think:
“Perfect square corner.”
Non-Right Angles
Non-right angles are angles that are not 90 degrees.
Non-right angles are angles that are too small or too wide to be a square corner.
👉 Examples:
Acute angle – smaller than a right angle
Obtuse angle – larger than a right angle
🧠 Think:
“Not a square corner.”
Watch this Video!
Group Activity
How to work together:
-
Work in groups of three.
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Talk about each problem before writing the answer.
-
One person types, another checks, and another explains the steps.
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Show working for every question.
