How to Find the Missing Side

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How to Find the Missing Side

• By
• Mrs. G

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First thing first

• Do I know the rule of the rectangle?
• The opposite sides are congruent or equal
• So that means the widths are the same and so are
  the lengths

• 6 in is the length
• 4 in is the width

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Use that rule to find the missing side

• 15 cm
• 4cm
• 9 cm
• ?
• 8cm ?

• Ok lets see if I got it
• I remember the rules of a rectangle.
• Knowing opposite sides are equal.
• So then what?
• Well, draw a dotted line so complete the
  rectangle and find the missing sides, using your
  rules of a rectangle.

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Finding the Missing Side

• 15cm
• 9 cm 4cm
• ?1
• 8cm ?2

• Draw your dotted line as if completing the
  rectangle.
• I know that the length is 15, and since the
  opposite side is equal.
• A piece is already given, which is 8.
• So if they are equal than ?1 must be 7cm (15-87)
  
• Following the same rule, the width is given 9cm.
• That must mean the opposite side is equal to
  that, so 9-45cm, so ?2 must be 5cm

5
Recap

• First I look at what is given and decide my
  length and width.
• Then, I remember my rule of a rectangle.
• Opposite sides are congruent or equal.
• Next, I draw a dotted line to complete my
  imaginary rectangle
• Finally as long as I remember my rule of a
  rectangle, I can find the missing sides, by
  subtracting the whole of one side from the piece
  of the other side.

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By Golly I Think You Got It