Geometry: Calculating Measurements

Objectives:

• Students will review previously learned terms.

• Students will review line segments and measurement.

• Students will use algebra to calculate line segments.

Suggested Grades:

Seventh Grade - Eighth Grade - Ninth Grade - Tenth Grade - including special education students

Lesson Procedure:

Print the classroom lesson plan and worksheet questions (see below).

Lesson Excerpt:

Calculating Measurements Using Algebra
Now, we are going to integrate algebra and geometry together. We will still be calculating the measurement of different line segments, but we will use algebra to do this. Let's look at an example.

(example line segment)

Now when you look at this line segment, you can see that it has been divided into four equal parts. Let's begin by writing some statements to describe this line segment.

• The line segment has been divided into four equal parts.
• There are five points that have been labeled on the line.
• Points A, B, C, D and E are collinear.
• Line segment AB is equal to BC
• BC is equal to CD
• CD is equal to DE

The fact that each of the small line segments are equal, introduces a vocabulary word that we have learned before -- congruent. When two lines, shapes or figures are exactly the same we can say that they are congruent.

Continued...