Polygons and Review

mathland · 2021-05-13 08:58:19

demha wrote:

Just need some help understanding some of these math problems and checking the ones I already did (if right/wrong). Thank you for your time:
1. An equilateral triangle with a side of 1 inch - Answer: A
A 0.43 sq in
B 0.56 sq in
C 0.89 sq in
D 0.23 sq in
E 0.19 sq in
F 0.54 sq in

2. A square with a side of 2 feet - Answer: B
A 9 sq ft
B 4 sq ft
C 2 sq ft
D 7 sq ft
E 3 sq ft
F 8 sq ft

3. A regular pentagon with a side of 3 centimeters - Answer: F
A 23.01 sq cm
B 12.34 sq cm
C 39.17 sq cm
D 9.46 sq cm
E 34.21 sq cm
F 15.48 sq cm

4. A regular hexagon with a side of 10 cm - Answer: D
A 641.25 sq cm
B 194.45 sq cm
C 361.25 sq cm
D 259.81 sq cm
E 105.22 sq cm
F 453.01 sq cm

5. A regular heptagon with a side of 7 inches. ***need help understanding how to solve***
A 178.06 sq in
B 294.16 sq in
C 169.21 sq in
D 358.91 sq in
E 157.36 sq in
F 277.91 sq in

6. A trapezoid where the height is 18 cm, base 1 = 16 cm and b2 = 8 cm. - Answer: C
A 178.06 sq cm
B 122.5 sq cm
C 216 sq cm
D 230 sq cm
E 280.9 sq cm
F 510 sq cm

7. A trapezoid where the height = 7 mm, base 1 = 26 mm and base 2 = 9 mm. - Answer: B
A 178.06 sq mm
B 122.5 sq mm
C 216 sq mm
D 230 sq mm
E 28.9 mm
F 510 mm

Fill in the missing information for the following trapezoids:
8.
height = 19.8 cm
b1 = ________
b2 = 14.4 cm
area = 401.94 cm2 - Answer: A
A 26.2 cm
B 12.5 cm
C 216 cm
D 23 cm
E 28.9 cm
F 51 cm

9.
height = 23 mm
b1 = 23 mm
b2 = ________
area = 529 mm2 - Answer: D
A 78.06 sq mm
B 22.5 sq mm
C 21.6 mm
D 23 mm
E 28.9 mm
F 30 mm^2

10.
height = ________
b1 = 20 cm
b2 = 21 cm
area = 205 cm2 - Answer: D
A 17.06 cm
B 12.5 sq cm
C 26 cm
D 10 cm
E 28.9 cm
F 50 cm^2

11.
height = 28.9 m
b1 = 26.9 m
b2 = ________
area = 806.31 m^2 - Answer: E
A 17.06 sq m
B 15 m
C 46 m
D 23 m
E 28.9 m
F 51 m

12. If the area of a parallelogram is 690.84 m^2 and the height is 20.2 m, what is the length of the base? - Answer: D
A 78.06 m
B 22.5 m
C 216 m
D 34.2 m
E 28.9 m
F 51 m

13. If the base of a rectangle is 28 cm and the area is 588 cm^2, what is the height of the rectangle? - Answer: E
A 17.06 cm
B 122.5 sq cm
C 216 sq cm
D 23 cm
E 21 cm
F 51 cm^2

14. If the height of a rectangle is 26.1 m and the base is 17.3 m, what is the area of the rectangle? - Answer: A
A 451.53 m^2
B 122.5 m^2
C 216 m^2
D 430 m^2
E 289 m^2
F 510 m^2

15. If the height of a parallelogram is 34 cm and the base is 15 cm, what is the area of the parallelogram? - Answer: F
A 178.06 cm^2
B 122.5 cm^2
C 216 cm^2
D 230 cm^2
E 289 cm^2
F 510 cm^2

16. What is the area of a parallelogram with height 26 cm, base 16 cm, and side length 28 cm?***need help understanding how to solve***
A 178.06 sq cm
B 122.5 sq cm
C 216 sq cm
D 416 cm^2
E 28.9 cm
F 510 cm^2

17. What is the area of a regular octagon with a side of 6 cm? ***need help understanding how to solve***
A 178.06 sq cm
B 122.5 sq cm
C 216 sq cm
D 23 cm^2
E 173.82 cm^2
F 510 cm^2

18. What is the area of this polygon?***need help understanding how to solve***
http://www.compuhigh.com/linkme/admin/testeditor/upload/pics/geometry/lesson21/area1.gif

ls_XF = 53 mm ls_XV = 72 mm ls_VR = 16 mm
ls_FB = 31 mm ls_BT = 31 mm ls_EU = 47 mm
ls_UL = 31 mm ls_TL = 88 mm ls_DE = 16 mm
ls_RM = 70 mm ls_MC = 21 mm ls_DC = 70 mm

A 8014 mm2
B7030 mm2
C6027 mm2
D5478 mm2
E 1782 mm2
F 1225 mm2

19. What is the area of this rectangle?***need help understanding how to solve***
http://www.compuhigh.com/linkme/admin/testeditor/upload/pics/geometry/lesson21/area2.jpg

A 17.06 sq units
B60 sq units
C21.6 sq units
D53 sq units
E 28.9 sq units
F 51 sq units

20. What is the area of this polygon?***need help understanding how to solve***
http://www.compuhigh.com/linkme/admin/testeditor/upload/pics/geometry/lesson21/area3.jpg

A 178 sq units
B129 sq units
C230 sq units
D240 sq units
E 219 sq units
F 206 sq units

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Not Dav · 2021-05-13 09:05:27

3 things,

1. This was from about 8 years ago

2. The question being asked right now is only asking for one of the questions not all.

3. I dont think the original poster is active anymore

Hope this helps

mathland · 2021-05-13 10:37:52

Not Dav wrote:

3 things,
1. This was from about 8 years ago
2. The question being asked right now is only asking for one of the questions not all.
3. I dont think the original poster is active anymore
Hope this helps

Thanks for clearing this up for me.

Bob · 2021-05-13 10:54:36

hi Peccatrix123

I understand EA, BC, CD, I'm just confused by where point F is. Is F where the shape kind of slants?
Also, would FC be 12?

If you continue the line AB until it crosses CD, that is the point F.

The four points EAFD make a rectangle. It looks like you have got this, because FC is 12, well done.

And BCF is a right angled triangle.

So now use Pythagoras' theorem to calculate BF. You'll have all the measurements you need to calculate the two areas.

Bob

mathland · 2021-05-13 18:02:13

Bob wrote:

hi Peccatrix123
I understand EA, BC, CD, I'm just confused by where point F is. Is F where the shape kind of slants?
Also, would FC be 12?
If you continue the line AB until it crosses CD, that is the point F.
The four points EAFD make a rectangle. It looks like you have got this, because FC is 12, well done.
And BCF is a right angled triangle.
So now use Pythagoras' theorem to calculate BF. You'll have all the measurements you need to calculate the two areas.
Bob

Hello Bob. About how many questions belong to the Unanswered section? Does it make sense to answer unanswered questions posted prior to the current year?

Thanks.

P. S. I really think this forum would benefit more if it was divided by courses. This is simply my opinion. Take a look at freemathhelp.com or mathhelpboard.com and others like it.

Peccatrix123 · 2021-05-14 03:15:37

Bob wrote:

hi Peccatrix123
I understand EA, BC, CD, I'm just confused by where point F is. Is F where the shape kind of slants?
Also, would FC be 12?
If you continue the line AB until it crosses CD, that is the point F.
The four points EAFD makes a rectangle. It looks like you have got this, because FC is 12, well done.
And BCF is a right-angled triangle.
So now use Pythagoras' theorem to calculate BF. You'll have all the measurements you need to calculate the two areas.
Bob

Hello sir,
Using pythag, I solved for AF which I got 9. Then I solved for the area of the triangle(0.5 x12x9) which I got 54. For the area of the rectangle EAFD, I'm confused. What is FD? I know EA is 8, but do I have to use pythag also to find FD?

Thanks,
J

Last edited by Peccatrix123 (2021-05-14 04:56:35)

Bob · 2021-05-14 05:00:23

hi J

%4 is good for the triangle.

Shape EAFD is a rectangle. EA was given as 8. AF = AB + BF.

You got 9 for BF (although you wrote AF). So AF = 10 + 9.

Nearly there.

Bob

Peccatrix123 · 2021-05-14 06:15:04

Bob wrote:

hi J
%4 is good for the triangle.
Shape EAFD is a rectangle. EA was given as 8. AF = AB + BF.
You got 9 for BF (although you wrote AF). So AF = 10 + 9.
Nearly there.
Bob

Hello Sir,

So the area of the rectangle EAFD would be 152(8x19)

Now I would add both areas together which would be:
152+54=206
So my final answer would be 206

Bob · 2021-05-14 08:33:40

Correct! Well done!

Bob

Peccatrix123 · 2021-05-14 09:47:34

Thank you very much, Sir! Have a good day and thank you for helping so many people with math free of charge!

Bob · 2021-05-14 21:33:32

You're welcome.

Bob

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