Neuschwander, C. (2001). *Sir cumference and the great knight of angleland* (W. Geehan, Illustrator).* *Watertown, MA: Charlesbridge Publishing.

**Summary:** Radius, the son of Sir Cumference and Lady Di of Ameter, goes on a knightly adventure where he uses his knowledge of angles to complete his quest.

**Quantitative Reading Level**: Lexile Level AD450L*, ATOS Level 4.2, Flesch-Kincaid Level 4.5

**Lexile Levels with AD mean that the title is often “adult directed” or read aloud by an adult.*

**Qualitative Reading Level**: Written with young math students in mind, this book uses illustrations and mnemonic devices to teach basic geometric concepts, such as right, obtuse, and acute angles; radius; and circumference. It uses simple, fun techniques to explain each concept. For example, the “obtuse mountains” have wide angles and the steep roofs of the village are “cute”—or *acute. *The text structure is simple, and it uses illustrations to support the narrative’s single plot line. The vocabulary is moderately complex in that the mathematical terms may or may not be familiar to readers. There is a single level of meaning throughout, but word play such of “Lady Di of Ameter” does add a measure of complexity for for older readers who have prior knowledge about the math concepts. The experiences portrayed will be familiar to young readers who have read other fairy tales or heroic adventures.

**Personal Thoughts**: This book is a fun way to learn math! The English teacher in me loves the word play and the hero’s journey plot. I believe this book would have helped me with my math anxiety as a young person. Any book that uses dragons to explain parallel lines is one that I can enthusiastically endorse.

**Content Area**: math (geometry)

**Teaching Suggestion: **Read this book aloud as an introduction to the concepts *radius, diameter, circumference, right angle, acute angle, obtuse angle, *and *parallelogram. *Or use it as reinforcement for students who have already learned basic geometry concepts. To assess student learning, ask them to summarize how Radius completed his quest. Ask that the summaries include the mathematical terms Radius needed for his adventure.

**Series Information**: *Sir Cumference and the Great Knight of Angleland *is the third in a series of 6 books about Sir Cumference and his mathematical adventures.

**Digital Resources**:

- Khan Academy Basic Geometry
- Smoop Basic Geometry

**Common Core State Standards:**

Compose two-dimensional shapes (rectangles, squares, trapezoids, triangles, half-circles, and quarter-circles) or three-dimensional shapes (cubes, right rectangular prisms, right circular cones, and right circular cylinders) to create a composite shape, and compose new shapes from the composite shape.

^{1}

CCSS.MATH.CONTENT.2.G.A.1

Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces.^{1} Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.

CCSS.MATH.CONTENT.3.G.A.1

Understand that shapes in different categories (e.g., rhombuses, rectangles, and others) may share attributes (e.g., having four sides), and that the shared attributes can define a larger category (e.g., quadrilaterals). Recognize rhombuses, rectangles, and squares as examples of quadrilaterals, and draw examples of quadrilaterals that do not belong to any of these subcategories.

Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.

Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles.

CCSS.MATH.CONTENT.5.G.B.3

Understand that attributes belonging to a category of two-dimensional figures also belong to all subcategories of that category. For example, all rectangles have four right angles and squares are rectangles, so all squares have four right angles.

CCSS.MATH.CONTENT.6.G.A.1

Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles or decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.

CCSS.MATH.CONTENT.7.G.B.4

Know the formulas for the area and circumference of a circle and use them to solve problems; give an informal derivation of the relationship between the circumference and area of a circle.