Transcript CI-JH-LP-SO- FINAL

How tall it is?
Shelia O’Connor, Josh Headley,
Carlton Ivy, Lauren Parsons
Pre-AP Geometry
1st period
8 March 2011
1
Shelia O’Connor- 60 °
30º
X
60º
90º
≈5 ft.
≈ 5.08 ft.
Solve with special right triangles
- Long leg = short leg*√3
- Short leg ≈ 5 ft.
- Long leg = 5√3
- Height = 5√3 + 5.08
Solve with Trigonometry
- tan(60) = x/5
- X = tan(60)*5
- X ≈ 8.66
- Height = 8.66 + 5.08
- Height ≈ 13.74
2
Josh Headley-20 °
Solve with Trigonometry
- tan(20)=x/36
- X=tan(20)36
- X=13.1
- 13.1+5.33
- Height ≈18.43
Solve with special Right Triangle
-can’t use special right triangle.
70º
x
20º
90º
≈36ft.
≈5.33
3
Carlton Ivy-30 °
Solve with Special Right Triangles
- l.leg=sh.leg√3
- 20=sh.leg√3
60º
x
≈20 ft.
- 20√3/3=sh.leg
- sh.leg=20√3/3+5.25
90º
30º
- 20/√3=sh.leg
- Height = 20√3/3+5.25
≈5.25 ft
Solve with Trigonometry
- tan(30)=x/20
- x=tan(30)20
- x=11.55+5.25
- Height≈16.8
4
Lauren Parsons-45 °
Solve with special right triangles
Leg = leg
Leg 1 ≈ 12 ft.
Leg 2=height1
Height2 ≈ 5.17 ft.
Total height= height1+height2
Total height ≈17.17 ft.
Solve with Trigonometry
tan(45)= x/12
X = tan(45)*12
X = 12
Height = 12 + 5.17
Total Height ≈17.17 ft.
45 °
x
45 °
≈12 ft.
90 °
≈5.17
5
Conclusion
In order to determine the height of the lamp
post, we applied special right triangles and
trigonometry. First we used clinometers to
measure an angle and to form a triangle. We
formed 4 triangles: 30º, 60º, 45º, and 20º.
Next, we measured the height to our eyes and
the distance to the pole. Then we used
trigonometry or special right triangles to
determine the portion of our triangle that made
up the height of the pole. Lastly we added our
height to determine the total height of the pole.
Average Height
≈16.26 ft.
Lesson learned: This process is not entirely
accurate because each triangle resulted in a
different height; however, this process is a
good way to approximate the height of an
object which is too tall to measure.
6