Pentominos
What do pentominos have to do with geometry?
NCTM

National Council of Teachers of Mathematics (NCTM) Standards
3-5
Geometry
3-5.8.0 Analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationships.
3-5.8.1. identify, compare, and analyze attributes of two- and three-dimensional shapes and develop vocabulary to describe the attributes.
Problem Solving
3-5.18.2. solve problems that arise in mathematics and in other contexts.
Connections
3-5.21.1. recognize and use connections among mathematical ideas.
6-8
Geometry
6-8.8.0 Analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationships.
6-8.8.1. precisely describe, classify, and understand relationships among types of two- and three-dimensional objects using their defining properties.
6-8.11.0 Use visualization, spatial reasoning, and geometric modeling to solve problems.
6-8.11.5. recognize and apply geometric ideas and relationships in areas outside the mathematics classroom, such as art, science, and everyday life.
Problem Solving
6-8.18.2. solve problems that arise in mathematics and in other contexts.