Mississippi Math FA.G.39
The Standard
Solve real-world and mathematical problems involving two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms. (7.G.6)
2025 Mississippi College- and Career-Readiness Standards for Mathematics
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students break drawings made of triangles and other polygons into parts, then add or subtract areas. For solids made of cubes or right prisms, they find volume or outside surface area and label the units.
What Mastery Looks Like
- Given an L-shaped floor plan, a student marks dimensions, splits it into rectangles, and finds the area without counting any space twice. Given two joined boxes, they add volumes and leave out the touching faces when finding outside surface area.
Common Misconceptions
- Students may count the hidden faces where two boxes touch. They may mix up square and cubic units, or use a slanted side instead of a triangle's height.
How to Assess It
- A 6 cm by 4 cm by 3 cm box has a 2 cm by 2 cm by 3 cm box attached along a 2 cm by 3 cm patch. Find the combined volume and outside surface area, and show how you handled the shared face.
Lesson moves
Ways to Teach It
Cut a 4 by 6 rectangle and two right triangles from grid paper, join edges without overlap, then find the new polygon's area.
Draw an 8 by 6 rectangle missing a 3 by 2 corner; ask students to explain both subtraction and split-and-add methods.
Race to match a 3 by 4 by 5 prism card with volume and surface area cards labeled 60 cubic units and 94 square units.
Stack two shoe boxes, measure their dimensions and shared patch, then estimate wrapping paper for the outside and storage space inside.
Free download
Printable FA.G.39 Worksheet
A ready-to-print activity worksheet aligned to FA.G.39, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetKeep exploring
Related Standards
- 7.G.6
Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals a...
- FA.G.36
Explain and apply the Pythagorean Theorem to determine unknown side lengths in right triangles in real-world and mathematical problems in two and three dimensio...
Turn this exact standard into a lesson
Grade, subject, topic, and the complete standard are prefilled. Create one free, no account needed.
Also for this standard:Make a WorksheetMake a QuizMake a Sub Lesson