Download Lesson Plan - About Manchester

Lesson Plan
Danielle Cancelli
Lesson: Angles Within Triangles
Length: 45 minutes
Age or Grade Level Intended: 6th Grade
Academic Standard(s):
Geometry Standard 4
6.4.4 Understand that the sum of the interior angles of any triangle is 180º and the sum of the
interior angles of any quadrilateral is 360º. Use this information to solve problems.
Performance Objective(s):
The sixth graders will correctly identify the measures of nine out of ten missing angles of
different triangles when given a corresponding worksheet.
Assessment:
Students will be given a worksheet with ten math problems. They will be assessed by the
completion and correction of each problem on the worksheet. They will be evaluated by the
amount of problems that are answered correctly. If the student correctly answers the problems on
the worksheet, full credit will be given. Students will be expected to answer sixteen out of the
twenty problems that they are given.
Advance Preparation by Teacher:
Materials:
Triangle Cutouts
Worksheets
Dry Erase Board
Dry Erase Markers
Preparation:
To prepare for the lesson, make sure that there are enough copies of the worksheet for each
student (worksheet is attached). Also make sure that there are enough triangle cutouts for each
student. Before the students arrive, write some sample problems on the board (attached) that you
will discuss with the students before the worksheet is given to them.
Procedure:
Introduction/Motivation:
Begin the lesson by reviewing the previous lesson about complementary and supplementary
angles. Refresh the students’ memories on how to create both types of angles. Then explain to
the students that each triangle has three interior angles that add up to a total of 180º. Do the
example problems that are written on the board with the class. Answer any questions they may
have regarding those problems or the information that you covered.
Step-by-Step Plan:
1. Draw the example problems on the dry erase board.
2. Do the example problems with the entire class. Make sure they understand that for every
triangle, the three interior angles sum up to 180º (Bloom Level I Knowledge).
3. Pass out the triangle cutouts to each student.
4. Then tell the students to open up their books to the section on Angles In Triangles. There
is an activity in the section that explains the sum of all the angles inside of a triangle.
Read aloud with the students the directions for the activity. It will help them understand
and absorb the information more easily. Explain each step thoroughly with the triangle
cutouts (Bloom Level II Comprehension) (Gardner Linguistic):
a. Label the three corners of the triangle cutout with the numbers 1, 2, and 3.
(Bloom Level I Knowledge)
b. Rearrange the torn pieces so that the corners all meet at one point. Notice that
together they form a straight line, which equals 180º (Gardner
Logical/Mathematical).
5. Ask the class if they have any questions on why or how the angles add up to 180º.
6. Pass out the worksheets to the students. (Attached).
7. Have the students independently complete (Gardner Intrapersonal) the worksheet
problems based on what they have learned and assist those who need help (Bloom Level
III Application) (Gardner Logical/Mathematical).
Closure:
At the end of class, ask the students if they have any questions or need help with understanding
the angles within a triangle. If they do need help, spend the last amount of class time working
with them. If they do not need help, review what the students learned throughout the class by
asking them questions (Bloom Level II Comprehension).
.
1. How many angles are there in a triangle?
2. What do the angles of each triangle add up to?
Self-Reflection:
Was I prepared for the lesson?
Were the students engaged?
What could I have done to improve the lesson?
Did the students easily understand the instructions?
Was there enough time given to complete the lesson?
Did the students learn from the lesson?
Do the students understand that three angles of each triangle sum up to 180º?
Adaptations/Enrichment:
Student with ADHD:




The hands-on activity will help the student with ADHD stay focused and interested in the
lesson.
The directions are also brief and to the point. That way the student will be able to keep
their focus on the directions and completely understand what they have to do.
The lesson includes both verbal and written directions, which means the student has more
than one way of receiving information. If he/she doesn’t hear all of the information that
is verbally given, there is also written directions that may be followed.
Positive reinforcement will also help the student with ADHD because it will give
encouragement, if needed.
Name __________________________
Angles In Triangles
Directions: Two angles of a triangle are given. Find the remaining missing angle.
1. 65º, 25º
_______________
2. 72º, 80º
_______________
3. 104º, 16º
_______________
4. 90º, 50º
_______________
5. 16º, 74º
_______________
6. 60º, 40º
_______________
7. 43º, 47º
_______________
8. 150º, 15º
_______________
9. 5º, 100º
_______________
10. 25º, 85º
_______________
SAMPLE PROBLEMS (write on dry erase board before class)
85º
35º
?
60º
90º
?
?
45º
45º