Lesson is designed for two days
Grade Level: 8
Materials: Pens, paper, pencil, calculator, tables, overhead, chalkboard, tape , foot, helicopter and brochure from Miami Seaquarium.
Objectives: The student, after the teacher's explanation and demonstration on finding the length of the third side of a right triangle, will be able to calculate the distance between the two points. This is known as the hypotenuse side of a right triangle.
Mathematical Concepts:
Right triangle, Hypotenus, Legs, Square, Square Roots, Distance, Geometry
NCTM Standards:
Standard 4: Mathematical connection
Standard 5: Number and Number Relationship
Standard 6: Number System & Number Theory
Standard 7: Computation and Estimation
Standard 8: Patterns and Functions
Standard 13: Measurements
Procedures :
1. Field trip to the Miami Seaquarium.
2. Have students get into small groups of 3-4 students.
3. Teacher demonstrates the way how to obtain the distances by
using the measuring tape or by using their feet.
4. The teacher picks two points A and B measures
the distance between the two points and log in the distance.
5. The teacher picks two more points B and C with B as the
previous point and C as the new point C, measures and records the
distances. Now we have the measurements for two sides of
the triangle This process is done until the students have obtained
all the measurements.
6. The teacher shows the students how to use this information and
assuming that the shape is a right angle triangular use the data
collected and the given formula c2 = a2 + b2
to find the missing side.
7. The teacher will explain to the class that the side "c" is
the length of the hypotenuse side , "b" is one of the
given side adjacent to the hypotenuse side and the other side "a"
is opposite to the hypotenuse side. The sides of the triangles are
called "legs".
8. The students will follow the directions of the teacher and find the
sides of each assigned triangles. The teacher will let
the students know that they are dealing with right angle triangles.
9. Explains to the students that a right angle triangle is
900
Assessment :
(a) Given a right angle triangle ABC , side AB = 3 feet, and BC = 4 feet .
Calculate the distance of side CA.
( Hint angle "B" is a right angle, it is equal to 900)
(b) Given a right angle triangle DEF, side DE = 6 feet, and EF = 8 feet.
Calculate the distance of side DF
( Hint: angle "E" is the right angle)
(c) The height of the flag pole is 12 feet, the distance
from the base of the flag pole to the curb is 16 feet. Calculate
the distance from the top of the pole to the curb.
Name your triangle with letters. (Note that the hypotenuse side is opposite to the right angle)
References: Miami Administrations, Architects,
Personnel office for Seaquarium, Phone number (305) 361 - 5705
Address: 4400 Rickenbacker Cswy., Miami, Florida 33149
Web Site: http://orchid.isle.com/adventur/aquarium.htm
Harcourt Brace Jovanoich: Mathematics Plus, 1993 , grade 7, p. 244 - 245. Authors: Grace M. Burton, Ph.D. Professor in the Department of Curricular Studies at University of North Carolina. Howard C. Johnson, Ph.D. Chairman of Mathematics Education at Syracuse Universit.
Contributors:Major: Mignon L. Griffith, Mathematics
teacher, West Miami Middle School
Minor: Carol A. Marinas, Professor of Mathematics and Computer Science
at Barry University
Rosa Rivas, Chairperson Mathematics Department, at West Miami Middle School.
Use table to record all of the measurements
Right Triangle Length of Length of Length of
first side second side third side
( Legs ) ( Legs ) ( hypotenuse )
Some extra problems
1. Given a side AB of length 15 feet and the side BC of length 45 feet, where the end point of the side BC lies across a canal. Find the length of the side AC . Note the triangle is a right angle triangle. (Hint: student can use a boat to go over to the other side of the canal and measure the distance.)
2. Given the hypotenuse side of the triangle AB with side equals 25 feet, the length of another side BC of the triangle is 15 feet. Find the length of the third side AC.