# Perimeter of the Lovely El “What is the perimeter of this shape?” (all the angles are 90 degrees )

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Perimeter of the Lovely El “What is the perimeter of this shape?” (all the angles are 90 degrees )

Perimeter of the Lovely El “Perimeter: the distance around an area.”

It doesn’t have to be a “regular” shape, either.

The perimeter around Parkland College is 1.45 miles

“Peri” means “around. 8 cm 7 cm 4 cm 6 cm 2 cm 1 cm “perinatal” means “happening around the birth time” “perimeter” means “measuring around a shape.”

8 units 7 units 6 units 2 units 1 unit The units have to be the same thing. If one side is measured in centimeters and the other in inches or feet or miles, adding the numbers together would just give you a number, not the answer to a question. (It’s same to same in the addition game!) 4 units

Perimeter: Add the distances of each side. 8 units 7 units 4 units 6 units 2 units 1 unit Notice that you’re measuring a distance, so your starting point is 0, not one. You’re counting the spaces – the distance – not the lines used to mark each unit.

What if we don’t know all the distances? 6 units 3 units 0 We don’t have to measure them. We can still figure things out, because as long as those angles are 90 degree “perfect corners,” we can use what we know about Parts and Wholes and … just watch 4 units 2 units

What if we don’t know all the distances? 6 units 3 units 0 4 units 2 units Trace these lines with your finger. They’re “parallel” – going *exactly* the same vertical (up and down) direction. They’d never meet even if they went on forever to infinity.

What if we don’t know all the distances? 6 units 3 units 0 4 units 2 units Which distance is the whole way from top to bottom? I’m the whole! Me!

What if we don’t know all the distances? 6 units 3 units 0 4 units 2 units The part we’re looking for… where is it? ? I’m the missing *part* I’m the whole! Me!

What if we don’t know all the distances? 6 units 3 units 0 4 units 2 units The part you already know is … where? I’m the missing *part* I’m the part you know! I’m the whole! Me!

What if we don’t know all the distances? 6 units 3 units 0 4 units 2 units To find a part…. Subtract the part from the whole. Whole minus part = part I’m the missing *part* I’m the part you know! I’m the whole! Me!

One more time… 6 units 3 units 0 4 units 2 units First trace the lines to find the ones going the same direction. I’m the missing *part* I’m the part you know! I’m the whole! Me!

One more time… 6 units 3 units 0 4 units 2 units First trace the lines to find the ones going the same direction. Next, figure out which are the parts, and which is the whole. I’m the missing *part* I’m the part you know! I’m the whole! Me!

One more time… 6 units 3 units 0 4 units 2 units First trace the lines to find the ones going the same direction. Next, figure out which are the parts, and which is the whole. Subtract to find a missing part; add to find a whole. I’m the missing *part* I’m the part you know! I’m the whole! Me!

You might want to backtrack… 6 units 3 units 0 4 units 2 units Go through these steps … then figure out the other missing side! I’m the missing *part* I’m the part you know! I’m the whole! Me! ???? units

Some other resources http://www.bbc.co.uk/bitesize/ks3/maths/me asures/ http://www.bbc.co.uk/bitesize/ks3/maths/me asures/ Make all the practice worksheets you want http://www.worksheetworks.com/math/geom etry/measuring-figures/perimeter-area.html http://www.worksheetworks.com/math/geom etry/measuring-figures/perimeter-area.html

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