100cm make one metre
100,000
1760
5280
Approx 3280.8 feet
Add up the lengts of all four sides.
2*12 = 24 cm.
8 cm
Round it to the nearest metre by rounding it to the nearest 100 cm, then if you rounded down add 100 cm otherwise you rounded up and so subtract 100 cm to get to the farthest metre. eg 125 cm to the farthest metre: To the nearest metre 125 cm rounds down to 100 cm. Thus to the farthest metre, as rounded down add 100 cm to give 200 cm to the farthest metre.
An octagon has eight sides, so add up all the sides... 8 x 10cm = 80 cm
35
Using the cosine rule they are 73.37 degrees, 62.19 degrees and 44.44 degrees which all add up to 180 degrees
ANY triangle MUST add up to 180 degrees.