## HourglassMage Group Title 2. A parallelogram has the vertices (-1, 2), (4, 4), (2, -1) and (-3, -3). Determine what type of parallelogram [10 points]. Find the perimeter and area [20 points]. 3 months ago 3 months ago

1. HourglassMage Group Title

2. HourglassMage Group Title

That's what I got...but clearly it's not a parallelogram, so what am I doing wrong, and what do I need to do differently?

3. HourglassMage Group Title

4. ganeshie8 Group Title
5. ganeshie8 Group Title

^^thats how it should look. graphing is a very good idea, but u dont need to graph to solve this problem.

6. HourglassMage Group Title

Ohhh...duh. Apparently I'm going to be stupid today, brilliant. Thnx for the help! :)

7. ganeshie8 Group Title

u figured how to work the problem ?

8. HourglassMage Group Title

BTW, someone told me the answer to this problem was 12. Are they right? I got 4.2... √((3) – (0))² + ((0) – (3))² = √3² + -3² = √9 + 9 = √18 ≈ 4.2

9. HourglassMage Group Title

yes, I did

10. ganeshie8 Group Title

show me ur complete work

11. HourglassMage Group Title

For the first problem?

12. ganeshie8 Group Title

for both

13. HourglassMage Group Title

Ah...ok

14. ganeshie8 Group Title

what ever u have so far...

15. HourglassMage Group Title

just a mo, then

16. HourglassMage Group Title

17. HourglassMage Group Title

working on the second question now

18. ganeshie8 Group Title

Are you given instructions that u need to work it by graphing ?

19. HourglassMage Group Title

Yeah, they taught graphing and the distance formula and whatnot

20. ganeshie8 Group Title

no, i mean did the instructions specifically ask u to do this by graphing ?

21. ganeshie8 Group Title

cuz, u should NOT use graphing unless the instructions say so

22. ganeshie8 Group Title

the common/regular way to work this problem is by finding lengths of sides using distance formula and the slopes of sides using slope formula

23. HourglassMage Group Title
24. HourglassMage Group Title

Those were the directions they gave me

25. ganeshie8 Group Title

cool :) then you're right ! they want u work it by graphing

26. HourglassMage Group Title

Given that they gave me the graph, I would assume that they want me to solve it by graphing, but I also used the distance formula to find the lengths of the sides

27. HourglassMage Group Title

ok :)

28. ganeshie8 Group Title

good :) your length of sides, and perimeter are correct. but Area is wrong.

29. ganeshie8 Group Title

squaring sides will not give u Area for a rhombus.

30. HourglassMage Group Title

ohh..just looked it up A - diagonal x diagonal/2

31. ganeshie8 Group Title

Area of rhombus = $$\frac{1}{2} d_1 d_2$$

32. ganeshie8 Group Title

yes^

33. HourglassMage Group Title

Great, now I have to find the diagonals, lol

34. ganeshie8 Group Title

its easy from graph

35. ganeshie8 Group Title

horizontal diagonal = 3--3 = 6 vertical diagonal = 3--3 = 6

36. ganeshie8 Group Title

So, Area = $$\frac{1}{2} d_1 d_2 = \frac{1}{2} 6*6 = 18$$

37. ganeshie8 Group Title

And that makes the given rhombus a SQUARE !

38. ganeshie8 Group Title

so the given parallelogram is not just a rhombus, its also a SQUARE !

39. ganeshie8 Group Title

for the type of parallelogram , you should say that its a square

40. ganeshie8 Group Title

if that makes any sense..

41. HourglassMage Group Title

The parallelogram is a rhombus and a square?

42. ganeshie8 Group Title

just say its a SQUARE !

43. HourglassMage Group Title

rhomus: all equal sides, two pairs of equal angles square: equal sides, equal angles

44. HourglassMage Group Title

oh, ok

45. HourglassMage Group Title

Does that change my equation for the area, then?

46. ganeshie8 Group Title

all squares are parallelograms all squares are rhombuses all squares are rectangles all squares are quadrilaterals

47. ganeshie8 Group Title

a square is many things

48. ganeshie8 Group Title

yes it will change ur formula, but the answer will be same

49. HourglassMage Group Title

I see that, lol

50. ganeshie8 Group Title

let me modify it and give u

51. HourglassMage Group Title

it will be?

52. HourglassMage Group Title

ok

53. ganeshie8 Group Title

here is the corrected stuff for question 1 : http://prntscr.com/3euc4h

54. HourglassMage Group Title

55. HourglassMage Group Title

how do you find the diagonals inside a rhombus?

56. ganeshie8 Group Title

use the distance formula

57. HourglassMage Group Title

oh, its the same process, ok, hold on

58. ganeshie8 Group Title

ok, i presume u knw what a diagonal is :)

59. ganeshie8 Group Title

it just connects the opposite vertices

60. ganeshie8 Group Title

|dw:1398867292759:dw|

61. ganeshie8 Group Title

|dw:1398867314860:dw|

62. ganeshie8 Group Title

^^those two line segments joining opposite vertices are diagonals

63. HourglassMage Group Title

64. HourglassMage Group Title

Is that correct? I found it odd that I got the same area for #1 and #2...but maybe that's just a coincidence

65. ganeshie8 Group Title

diagonals are not equal in rhombus

66. ganeshie8 Group Title

so u need to calculate the 2nd diagonal also using distance formula

67. ganeshie8 Group Title

and then use the area of rhombus formula : Area = $$\frac{1}{2}d_1 d_2$$

68. HourglassMage Group Title

69. HourglassMage Group Title

@ganeshie8

70. ganeshie8 Group Title

looks good !

71. HourglassMage Group Title

thnx! :D