Measuring Angles CCGPS.4.MD.5Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement: a. An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1/360 of a circle is called a “one-degree angle,” and can be used to measure angles. b. An angle that turns through n one-degree angles is said to have an angle measure of n degrees. CCGPS.4.MD.6Measure angles in whole number degrees using a protractor. Sketch angles of specified measure. CCGPS.4.MD.7Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.
Reading a Protractor
Measuring Angles Within a Circle
Precise Measurement with a Protractor
Degrees in a Circle
Sketching Angles by Using a Protractor
Measuring Angles with a Protractor
Sketch Precise Angles
Click on the pictures below to view videos on measuring angles.
What's My Angle
Naming and Measuring Angles
Free Brainpop Video on Measuring Angles
Measuring an Angle- Advanced
Exploring Angles Using a Clock
Angle Games and Activities
Squirt the Dog
Shoot the Aliens
Click on the picture to watch a Cyberchase video on angles. Video is 23 minutes in length.
Click on image to view activities.
Geometry CCGPS. 4.G.1 Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
Identifying lines, points, and rays
Identifying Parallel, Perpendicular, and Intersecting Lines
Identify Attributes of Shapes
Drawing Shapes According to Attributes
Parallel and Perpendicular
Check your Understanding
Types of Lines
CCGPS.4.G.2 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.
Classifying 2-D Figures
Attributes of Quadrilaterals
Classifying Triangles by Their Properties
Classifying Right Triangles
CCGPS.4.G.3 Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry.