Download Document showing use of triangle and rubric.

File Document #1
FOREST
RANGER
STATION
?
OBSERVER
29°
CABIN
300 yards
An observer is standing at the edge of a lake and wishes to know the distance from a ranger
station on the opposite side of a lake to his cabin. He knows that the angle formed from his
observation point is 29° and the distance from his cabin to the observation point is 300 yards.
Use a trigonometric function to solve for the distance he wishes to find.
Solution
tan 29° = x/300
.5543 = x/300
166.29 = x
∴ The distance across the lake is ≈ 166.29 yards.
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03
File Document #2
The teacher will prepare a worksheet with 10 right triangles positioned in different ways.
The measure of one of the acute angles and the length of one side will be given. Students will be
asked to find the length of one of the remaining sides using one of the three basic trigonometric
functions. (sine, cosine and tangent)
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03
File Document #3
Appendix: How to Make an Inclinometer by Charlene Kincaid
Materials needed for each inclinometer:
Protractor
Small weight (flat washers work well)
Straw
Paper clip
Transparent Tape (or hot glue)
String or fishing line
Procedure:
1. Attach the straw to the straight edge of the protractor using the transparent tape or hot glue as
shown below. Be sure that the bottom edge of the straw is lined up with the 90o mark and is
perpendicular to the base edge of the protractor.
2. Attach the string using a paper clip, which has been folded open (in an S shape) so that it will
swing freely from the hole in the base of the protractor. If no hole is present, attach the string
to the straw at the center of the zero line on the protractor.
Student looks through
this end of the straw.
Paperclip
Washer or
weight of
some sort
String or
fishing line
How to use:
As students sight the top of their object through the tube – lining it up with the bottom
edge of the tube -- the angle of elevation should be noted by their partners. Have the students
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03
continue to hold the inclinometer steady, so that the angle can be read easily. You should have
the students practice doing this before they are given their assignment.
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03
File Document #4
This is the measuring process used to measure the flagpole.
Students will find this leg of the
right triangle using the tangent
function. They will then add
the height of the person holding
the inclinometer to find the
actual height of the flagpole.
This side of the right triangle is
the same as the yarn length on
the ground.
Angle measured by
the inclinometer
Student’s
height
Yarn on the
ground
Student groups will take their piece of yarn and lay it on the ground starting at the base of the flagpole and moving
out. They may repeat this over and over if they choose. Then using the inclinometer, measure the angle of elevation.
The recorder in the group will keep track of all the data.
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03
File Document #5
The teacher will score the worksheet with the 10 problems in this manner:
Problem set up with the correct trig ratio – 5 points each
Correct solution – 5 points each
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03
File Document #6
The final flagpole measurement should be graded in this manner:
Correct drawing – 10 points
All sides and angles used to do calculations labeled and correct – 20 points
Correct trig ratio used to solve for vertical leg of the right triangle – 20 points
Correct solving of the trig ratio – 20 points
Student’s height measured correctly and added to the answer in the step above – 10 points
Correct answer (within 4 ft. of actual height) – 20 points
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03
File Document #7
COOPERATIVE LEARNER CHECKLIST
RECORDER: (Records Information)_______________________________________________
QUESTIONER: (Only one person in the group is allowed to ask the teacher questions.)
_________________________________________________
MATERIAL PERSON: (Gets supplies) _____________________________________________
FACILITATOR: (Makes sure the group is following instructions)
_________________________________________________
CALCULATOR: (Does calculations) _______________________________________________
CHECKER: (Checks calculations)__________________________________________________
A student may have more than one job.
COMMENTS:
What part of this lab did you like the most?
What was the best part of your group?
How could your group have been improved?
You Can’t Go Wrong With A Right Triangle III
©2000-2003www.beaconlearningcenter.com
Rev.8.28.03