Euclid 1

1
Euclid 1
Find the point X where the lines joining A to B
and C to D cross.
Find the point Y where the lines joining A to C
and B to D cross.
C
B
?
?
A
?
?
D
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2
Euclid 2
Copy segment AB to line L starting at C.
B
A
C
?
L
Create segment DZ twice as long as AB starting at
D on line M.
D
?
M
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3
Euclid 3
Make a copy of triangle ABC.
C
A
B
Make up more triangles and copy them.
4
Euclid 4
Make a triangle with these three sides.
Make a triangle with these three sides.
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5
Euclid 5
Make two or three different quadrilaterals with
these four sides.
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6
Euclid 6
Find the right place for C so that ABC is an
equilateral triangle.
C
B
A
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7
Euclid 7
Find the point X that divides segment AB in
half. Remember no measuring! Ask for a hint if
you need one.
B
A
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8
Euclid 8
Find the midpoints X, Y and Z of the sides of
triangle ABC. Then draw AX, BY and CZ. What do
you notice?
C
Y
X
A
B
Z
Try this with some other triangles.
9
Euclid 9
Copy angle a (thats a Greek alpha) to point
A(thats A prime) Hint. You know how to copy
a triangle, so make one to copy.
a
A
A'
?
Try this with some other angles if you need more
practice..
10
Euclid 10
Make an angle at A thats twice as large as
a. Make an angle at B twice as large as ß. (This
is tricky)
ß
B
a
A
11
Euclid 11
Bisect (cut in half) angles a and ß (Greek
beta). Hint. Create isosceles triangles and
bisect their third sides
a
A
ß
B
12
Find the angle bisectors of each angle of this
triangle. What do you notice?
C
Euclid 12
B
A
Try this with some other triangles.
13
Euclid 13
Build a triangle with two angles a and ß. Then
check that the third angle of that triangle is
the same size as ?(gamma). Do you need a hint
about how to do the check? (Do this on another
sheet of paper.)
ß
?
a
14
Euclid 14
In this picture, angle a is a straight
angle. Bisect it. Now youve built a right
angle! Ask if you need a hint.
?
a
15
Euclid 15
Draw a line through point A that makes a right
angle with line L. Remember no guessing. Ask if
you need a hint.
?
A
L
16
Euclid 16
Draw a line through point A that is parallel to
line L. Hint. Draw any line through A and copy
the angle that line makes where it meets L.
A
?
L