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#1 Help Me ! » Areas of Polygons Review » 2019-03-24 01:17:10
- avaeliza
- Replies: 2
Hello! I have a lesson review that I need some help figuring out. I'll post 3-7 and then the next set if I still need help. Thanks 
For #1-7, calculate the area for each of the polygons described below. Round answers to the nearest hundredth and remember to include the unit of measure.
Stuck on #3 right now. Here's what I have so far:
#3. A regular pentagon with a side of 3 centimeters
2 x side angle + central angle = 180
2 x side angle + 72 = 180
2 x 54 + 72 = 180
tan(54) ?????????
I followed my teacher's example of a nonagon here:
Find the measure of one base angle.
central angle = 360/9 = 40
2 * side angle + central angle = 180
2 * side angle + 40 = 180
2 * side angle = 140
side angle = 70°
Use a trig ratio to find the height of one triangle.
tan(70°) = h/(8/2)
h = 4*tan(70°)
h = 10.99 in
I can't figure out what the h/8/2 part means.
I haven't tried 4-7 yet because I think I might run into the same issues.
#4. A regular hexagon with a side of 10 cm
#5. A regular heptagon with a side of 7 inches.
#6. A trapezoid where the height is 18 cm, base 1 = 16 cm and b2 = 8 cm.
#7. A trapezoid where the height = 7 mm, base 1 = 26 mm and base 2 = 9 mm.
#2 Introductions » trigonometry » 2018-10-18 22:29:29
- avaeliza
- Replies: 1
I can't figure out how to start these problems! I won't have an issue doing the problem but I'm not sure the formula for each of them. Please help! Thanks
1. A 30-60-90 triangle has a hypotenuse of 10. Use trig (sine, cosine, or tangent) to find the short side. Show your work.
2. A 30-60-90 triangle has a hypotenuse of 10. Use special right triangle formulas to find the long side. Explain your work.
3. A 30-60-90 triangle has a hypotenuse of 16 and a short side of 8. Use the Pythagorean theorem to find the third side. Show your work.
4. A 30-60-90 triangle has a hypotenuse of 16 and a short side of 8. Use special right angle formulas to find the third side. Explain your work. Does your answer match what you got on number 3?
5. A 45-45-90 triangle has a leg of 4[sqrt(2)]. What is the hypotenuse? Show and explain your work.
6. A right triangle has legs of 4 and 5. What is the hypotenuse? Show your work.
7. A right triangle has a hypotenuse of 13 and a leg of 8. What is the other leg? Show your work.
8. A 12-foot ladder is leaning across a fence and is touching a higher wall located 3 feet behind the fence. The ladder makes an angle of 60 degrees with the ground. Find the distance from the base of the ladder to the bottom of the fence. Show all of your work.
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