Download Circling 1.1

Geometry: Circling the Bases - Level 1
Lesson 1 – Pre-Visit
What’s Your Angle?
Objective: Students will be able to:
• Define point, line, line segment, and angle.
• Classify right, acute, and obtuse angles.
• Use a protractor to measure and draw angles.
Time Required: 1 class period
Materials Needed:
- Protractors
- Pencils
- Paper
- Copies of the “Identifying Angles” worksheet (included) - 1 for each student
- Copies of the “Baseball Diamond Angles” worksheet (included) – 1 for each
student
- A variety of colored pencils
- 3 sheets of poster board
- Index cards (2 for each student)
- Glue sticks or tape
Vocabulary:
Angle - The figure formed by two lines extending from the same point
Acute Angle - An angle measuring less than 90 degrees
Degree - A unit of measure for angles
Line Segment - A part of a straight line included between two points
Obtuse Angle - An angle measuring greater than 90 degree and less than 180 degrees
Point - A geometric element that has position but no dimensions and is pictured as a
small dot
Ray - A line that has one endpoint, with the other endpoint extending to infinity
Right Angle - An angle measuring exactly 90 degrees
Vertex - The point where two line segments or rays meet to form an angle
4
Geometry: Circling the Bases - Level 1
Applicable Common Core State Standards:
CCSS.Math.Content.4.G.A.1 Draw points, lines, line segments, rays, angles (right, acute,
obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.
CCSS.Math.Content.4.MD.C.5 Recognize angles as geometric shapes that are formed
wherever two rays share a common endpoint, and understand concepts of angle
measurement.
CCSS.Math.Content.4.MD.C.6 Measure angles in whole-number degrees using a
protractor. Sketch angles of specified measure.
5
Geometry: Circling the Bases - Level 1
Lesson
1. Begin the lesson by asking students to take out a piece of lined paper and fold it in
half vertically. Have students label the paper with the heading “Geometry
Dictionary.” Have them label the two columns created by the fold “Word” and
“Definition.” Students will use this dictionary throughout the unit as a reference,
adding more pages as necessary.
2. Explain that geometry is a branch of mathematics that deals with points, lines,
angles, and shapes.
3. Students may start their Geometry Dictionaries right away by recording the
definition of geometry.
4. Draw a diagram of a baseball infield on the board or on a sheet of chart paper.
5. Explain that a point is a geometric element that has position but no dimensions and
is pictured as a small dot. Use the example of a player standing on a baseball field.
Draw a point on the infield diagram drawn in the previous step. Have students add
the word “point” to their Geometry Dictionaries.
6. Next, explain that a line segment is a part of a straight line included between two
points. Use the example of one baseball player throwing a ball to another player.
Draw a second point on the infield diagram, and then draw a line segment between
the two points now on the diagram. Have students add the word “line segment” to
their Geometry Dictionaries.
7. Now, explain that an angle is a figure formed by two lines extending from the same
point. Using the infield diagram, show students that an angle on a baseball field is
created by the 1st and 3rd base lines (intersecting at home plate). Have students add
the word “angle” to their Geometry Dictionaries.
8. Explain the term “vertex” as the point at which the two line segments of an angle
meet. Have students add this word to their Geometry Dictionaries. Using the 1st and
3rd base line angle, show students that the vertex of the angle is home plate.
6
Geometry: Circling the Bases - Level 1
9. Draw two different angles on the board. Explain that in geometry, angles are
measured in units called degrees. Show students the symbol for degree.
10. Hand out protractors to all students. Show students how to use a protractor to
determine the measurement of a given angle.
11. Draw, describe, and define different types of angles:
- Right angle: An angle measuring exactly 90 degrees
- Acute angle: An angle measuring less than 90 degrees
- Obtuse angle: An angle measuring greater than 90 degree and less than 180
degrees
12. Have students record all four angle types in their Geometry Dictionaries.
13. Practice identifying angles around the classroom. Encourage students to look around
and find examples of obtuse, acute, and right angles.
14. Introduce the activity.
7
Geometry: Circling the Bases - Level 1
Activity
1. First, divide students into small groups of 3-4.
2. Provide each group with three “Baseball Diamond Angles” worksheets (included)
and a protractor. Have groups choose three different colored pencils to represent
three different types of angles (right, acute, obtuse).
3. Within their small groups, have students work together to create three different
types of angles on the three worksheets (one sheet for each angle). For each angle,
students should select three baseball positions (catcher, pitcher, first base, second
base, third base, shortstop, right field, left field, center field) and place a point at
each selected position.
4. Students should then connect the three points on their worksheet to form an angle
using the crayon or colored pencil of their choice. Finally, they should measure and
label the angle.
5. Collect students’ finished work. Organize the worksheets by angle type, hole punch
them, and connect them to form books of right, acute, and obtuse angles.
6. Next, pass out two index cards to each student. Have each student draw a different
angle on each of their index cards, but do not measure or label them.
7. When students have finished creating their angles, collect the cards. Mix them up
and redistribute them so that each student has two cards drawn by other students.
Now have students measure and label each card with the appropriate angle.
8. While students are working, bring out 3 sheets of poster board. Label each with the
name of a different type of angle (right, acute, obtuse). Hang them up around the
room.
9. Have students use glue sticks or tape to stick the angles they have labeled onto the
appropriate poster board.
8
Geometry: Circling the Bases - Level 1
Conclusion:
To conclude this lesson and check for understanding, for homework, have students
complete the “Identifying Angles” worksheet (included). Instruct students to use a
protractor to find the angle degree and the type of angle.
9
Geometry: Circling the Bases - Level 1
Identifying Angles
Name: __________________
Date: ______________
Instructions: Use a protractor to find the measure of each angle represented by
these batters’ stances. Then, identify the type of angle.
#1
#2
#3
#4
10
#5
1) Angle Degree __________
Type of Angle_______________
2) Angle Degree __________
Type of Angle_______________
3) Angle Degree __________
Type of Angle_______________
4) Angle Degree __________
Type of Angle_______________
5) Angle Degree __________
Type of Angle_______________
11
Geometry: Circling the Bases - Level 1
Identifying Angles Answer Key
1) Angle Degree ___70_____
Type of Angle__Acute_
2) Angle Degree ___90_____
Type of Angle__Right_
3) Angle Degree ___60_____
Type of Angle__Acute_
4) Angle Degree ___130____
Type of Angle__Obtuse
5) Angle Degree ___130____
Type of Angle__Obtuse
12
Geometry: Circling the Bases - Level 1
Baseball Diamond Angles
Team Names:
___________________
___________________
___________________
___________________
Angle Degree __________
Type of Angle_______________
13