## katlin95 2 years ago can someone help me with these 3 proofs, I have attached the file.. it has to get done by today! and i really appreciate it:) medals rewarded!

1. katlin95

2. katlin95

@roberman228

3. katlin95

okay:)

4. katlin95

5. katlin95

@whpalmer4 can you help?

6. katlin95

@jim_thompson5910 can you help me with these couple of questions about geometry proofs?

7. jim_thompson5910

how far did you get on #2

8. katlin95

um i think i finished that one, not sure let me check

9. jim_thompson5910

ok post what you got

10. katlin95

im not so sure how to do it?

11. jim_thompson5910

or just write it out here

12. katlin95

like what do you mean?

13. katlin95

# 2 im not sure what to do

14. katlin95

what is the first step i need to do @jim_thompson5910 ?

15. jim_thompson5910

16. katlin95

so would it be BCD=EDC BCD=ECD

17. katlin95

both are given?

18. jim_thompson5910

good, start off saying those two sets of angles are congruent because that's given

19. katlin95

so then it would look like this? BCD=EDC|GIVEN BCD=ECD|GIVEN and then now what?

20. jim_thompson5910

what segments can you say for sure are congruent

21. katlin95

uuhmm not so sure.

22. katlin95

i would have to say that BCD and BED are congruent right?

23. jim_thompson5910

what segment is between angles BCD and EDC

24. katlin95

is it just one segment?

25. jim_thompson5910

yes do you see it?

26. katlin95

CDE?

27. jim_thompson5910

segment, not angle

28. katlin95

F?

29. jim_thompson5910

that's a point, not a segment

30. katlin95

whats a segment?

31. jim_thompson5910

there's the figure |dw:1358891844771:dw|

32. jim_thompson5910

what I'm talking about is this segment (in black) |dw:1358891880746:dw|

33. katlin95

ohhh C and D sorry lol

34. jim_thompson5910

you mean segment CD right?

35. katlin95

yes hhaha lol

36. jim_thompson5910

that's the shared side between the two triangles that overlap

37. jim_thompson5910

CD = CD by the reflexive property

38. jim_thompson5910

then you can say those two overlapping triangles are congruent by the ASA property

39. katlin95

okay, so what would our whole overall problem look like? ill do it, and you see if it looks correct

40. jim_thompson5910

alright

41. katlin95

BCD=EDC|GIVEN BCD=ECD|GIVEN so CD=CD by the reflexive property the two overlapping triangles are congruent by the ASA property would this be what it look like?

42. jim_thompson5910

you'll have to be specific by actually naming the triangles

43. katlin95

BCD=EDC|GIVEN BCD=ECD|GIVEN so CD=CD by the reflexive property BCD and EDC are congruent by the ASA property how about this?^^

44. jim_thompson5910

you nailed it

45. katlin95

awesome! okay how about the next one now:)

46. jim_thompson5910

oh you might want to say triangles BCD and EDC are congruent by the ASA property so you don't confuse them with angles

47. katlin95

okay!

48. jim_thompson5910

ok how do we get started on the next one

49. katlin95

50. jim_thompson5910

exactly, so go ahead and state that

51. katlin95

im not sure how that to start this one because Ive never done one with a midpoint in it, but ill try real quik

52. jim_thompson5910

well you start off by stating that D is the midpoint of AC (given) then you use the definition of midpoint to say that AD = CD

53. katlin95

54. jim_thompson5910

where does it say that BCD=BAD is given?

55. katlin95

actually no lol

56. jim_thompson5910

but the first one is given

57. jim_thompson5910

58. katlin95

59. jim_thompson5910

AD = CD not because it's given, but by the definition of midpoint

60. jim_thompson5910

A midpoint cuts a line segment into two equal halves

61. katlin95

so then how do i find my other given?

62. jim_thompson5910

You're done with you're givens

63. katlin95

oh so theirs only one given then

64. jim_thompson5910

Now you need one more side or one more angle, here is a visual hint: |dw:1358892974213:dw|

65. jim_thompson5910

There are 2 givens, but you've used them up already

66. katlin95

so then if we have BDC=BDA|GIVEN I would have to look at the other angle i have on the picture to get my other given?

67. jim_thompson5910

|dw:1358893179414:dw|

68. katlin95

69. jim_thompson5910

see those segments i highlighted?

70. katlin95

yep

71. jim_thompson5910

they are congruent, do you see why?

72. katlin95

yes, because they have equal sides right?

73. jim_thompson5910

they are congruent because they are the same segment BD |dw:1358893344746:dw|

74. jim_thompson5910

so you'll have to say BD = BD and give a reason why that's true

75. katlin95

so I would say BD=BD are reflective property ?

76. jim_thompson5910

good

77. katlin95

okay and then I say why my triangles are congruent?

78. jim_thompson5910

yes and which property will you use

79. jim_thompson5910

this may help |dw:1358893552844:dw|

80. katlin95

so then it would look like this: BDC=BDA|GIVEN So BD=BD by the reflective property Triangles BDC and BDA are congruent by the ASA property is this right?

81. jim_thompson5910

you're missing something

82. jim_thompson5910

AD = DC but why is that?

83. jim_thompson5910

and remember you have 2 given statements

84. katlin95

because its the midpoint, where would i place it?

85. jim_thompson5910

and it's not the ASA property

86. katlin95

would it be the SAS property?

87. jim_thompson5910

yes that's correct

88. katlin95

BDC=BDA|GIVEN AD = DC|GIVEN So BD=BD by the reflective property Triangles BDC and BDA are congruent by the SAS property

89. jim_thompson5910

no AD = DC is not given

90. jim_thompson5910

go back and look at the doc and you'll see it's not given

91. katlin95

okay, so then what would our next given be and is SAS correct for the property?

92. jim_thompson5910

yes it's SAS

93. jim_thompson5910

look back at the doc, and simply restate what they give

94. katlin95

all i see is Dis the midpoint of side AC, and then BDC=BDA

95. jim_thompson5910

there you go

96. jim_thompson5910

just restate those and say given

97. jim_thompson5910

that will allow you say that AD = DC because of the definition of midpoint

98. katlin95

so how would it look ?

99. jim_thompson5910

100. katlin95

okay, where would I put that at when i put my answer in?

101. katlin95

so would it look like this: BDC=BDA|GIVEN side AD =side DC|GIVEN So BD=BD by the reflective property Triangles BDC and BDA are congruent by the SAS property

102. jim_thompson5910

put those givens at the top, then put AD = DC | definition of midpoint right after that

103. katlin95

oh okay!

104. katlin95

AD = DC | definition of midpoint BDC=BDA|GIVEN So BD=BD by the reflective property Triangles BDC and BDA are congruent by the SAS property

105. jim_thompson5910

you forgot AD = DC | definition of midpoint again

106. katlin95

BDC=BDA|GIVEN AD=DC|GIVEN AD = DC | definition of midpoint So BD=BD by the reflective property Triangles BDC and BDA are congruent by the SAS property

107. jim_thompson5910

good

108. katlin95

OK last one!:)

109. jim_thompson5910

ok show me what you got for this one

110. katlin95

kk

111. katlin95

I got: AB=CD|GIVEN BF=ED|GIVEN is this right?

112. jim_thompson5910

AB || CD, not AB = CD

113. jim_thompson5910

also, angle B = angle D | given

114. katlin95

so then it would look like this AB||CD|GIVEN angle B=angle D|given

115. jim_thompson5910

along with BF=ED|GIVEN

116. jim_thompson5910

you have 3 given statements

117. katlin95

oh how would i order them?

118. jim_thompson5910

in any order, all 3 are given and don't depend on one another

119. katlin95

AB||CD|GIVEN angle B=angle D|given BF=ED|GIVEN now what?

120. jim_thompson5910

because AB || CD, we can say that angle BAF = angle DCE because they are alternate interior angles

121. jim_thompson5910

so essentially angle BAF = angle DCE | alternate interior angles what's next?

122. jim_thompson5910

you have 2 angles, and a side, which congruence property can you use?

123. katlin95

BAF=angle DCE|alternate interior angles angle B=angle D|given BF=ED|GIVEN just to clear it up is this right^^ if its not can you correct it?

124. jim_thompson5910

you put the givens first though the "given" statements always come first

125. jim_thompson5910

126. jim_thompson5910

and you build from there

127. katlin95

BF=ED|GIVEN angle B=angle D|given BAF=angle DCE|alternate interior angles

128. jim_thompson5910

you forgot the line AB||CD | given

129. katlin95

where do i put that that at

130. jim_thompson5910

above the "alternate interior angles" line

131. katlin95

BF=ED|GIVEN angle B=angle D|given AB||CD | given BAF=angle DCE|alternate interior angles

132. jim_thompson5910

good

133. katlin95

okay now what:)

134. jim_thompson5910

you have 2 angles, and a side, which congruence property can you use?

135. katlin95

ASA OR AAS

136. jim_thompson5910

you would use AAS because the two angles are adjacent and the last side is not between them

137. katlin95

Ok, so then would i say anything about reflective property?

138. jim_thompson5910

no you can't use the reflexive property for this one

139. katlin95

so it looks like this: BF=ED|GIVEN angle B=angle D|given AB||CD | given BAF=angle DCE|alternate interior angles triangle BF and ED are congruent by the AAS property

140. jim_thompson5910

last line is more like triangle ABF and triangle CDE are congruent by the AAS property

141. katlin95

okay, but otherwise it looks good?

142. jim_thompson5910

yes it looks great

143. katlin95

thanks so much jim! you tha best:))

144. jim_thompson5910

you're welcome