• Chapter 5:
    Geometry and Measurement 
  • Overview 

    In this unit, students are formally introduced to a host of new geometric concepts, including angles and angle measure, parallel and perpendicular lines, and reflective symmetry. In Module 1, students focus on comparing, analyzing, classifying, and measuring angles. In Module 2, students investigate parallel and perpendicular lines as well as line symmetry and use these terms and concepts to sort and classify a wide variety of polygons. During Module 3, students measure the area and perimeter of rectangles, making generalizations that support the introduction of the formulas for both. Module 4 features a return to angle measure, with an emphasis on the fact that angles involve turns or rotations around a fixed point and are additive in nature. 

    Skills Across the Grade Levels 

    The table below shows the major skills and concepts addressed in Unit 5. It is meant to provide a quick snapshot of the expectations for students’ learning during this unit, as well as information about how these skills are addressed in Bridges Grade 3, elsewhere in Grade 4 including Number Corner (NC), and also in Grade 5. 

    Major Skills/Concepts Addressed Gr. 3 Unit 5 Gr. 4 Elsewhere Gr. 5 

    4.MD.3 Apply the area formula for a rectangle to solve a problem. 

    4.MD.5 Identify an angle as a geometric figure formed where two rays share a common endpoint. 

    4.MD.5a Measure angles by identifying the fraction of the circular arc between the points where the two rays forming the angle intersect the circle whose center is at the endpoints of those rays. 

    4.MD.5b Identify the measure of an angle by identifying the total number of one-degree angles through which it turns. 

    4.MD.6 Use a protractor to measure angles in whole degrees; sketch an angle of a specified measure. 

    4.MD.7 Decompose an angle into non-overlapping parts. 

    4.MD.7 Express the measure of an angle as the sum of the angle measures of the non-overlapping parts into which it has been decomposed. 

    4.MD.7 Solve problems involving finding the unknown angle in a diagram, using addition and subtraction. 

    4.MD.7 Demonstrate an understanding that angle measure is additive. 

    4.G.1 Identify points, lines, line segments, rays, and angles (right, acute, obtuse), parallel lines, and perpendicular lines in 2-D figures. 

    4.G.1 Draw angles (right, acute, and obtuse), parallel lines, and perpendicular lines. 

    4.G.2 Classify 2-D figures based on the presence or absence of parallel lines, perpendicular lines, and angles of a specified size; identify right triangles. 

    4.G.3 Identify and draw lines of symmetry; identify figures with line symmetry. 

    *Retrieved on July 21, 2021 from http://bridges.mathlearningcenter.org/