Question 201372
1) to  construct  a  new  equilateral  triangle  of  side "s", start with  the  existing  equilateral  triangle,  Extend  2  sides  until  they  are  "s" long, connect  these  points.
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2)altitude  is  perpendicular  distance  from  the vertex  to  the  opposite  side
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Median  is  the  distance from  the  vertex  to  the  opposite  side
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They  are  equal  in  isosceles(when  base  is  odd length)  or  equilateral  triangles
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3)Construction  easily  makes  180 degree  and  90 degree  angles.
bisection  or  repeated  bisection  yields,  45,  22.5,  11.25,  etc  angles
Adding  or  subtracting  from each  other  yields  combinations.
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a 30-60-90 triangle  has  sides of 1-2-sqrt3.  Constructing  a  30 degree  or  60 degree is readily  done  using  length  ratios  of  1  &2.  Bisecting  these   repeatedly  yields 15, 7.5, 3.75, etc.  degrees.  These  can  be  added  or  subtracted to  find  numerous  angles.