Geometry Key Words
Project Maths
Mr McCormack
Geometry Definitions
1.
Axiom
An Axiom is a statement which we accept without proof
2.
Theorem
A theorem is a rule that has been proved by following a certain
number of logical steps
3.
Proof
A Proof is a series of logical steps which we use to prove a
theorem
4.
Corollary
A Corollary is a statement that follows readily from a previous
theorem
Mr McCormack
Geometry
Converse
The converse of a theorem is the reverse of
the theorem
6. Implies
Implies is a term we use in a proof when we
can write down a fact we have proved from a
previous statement. Symbol is =>
7. Transversal
A transversal is a line which cuts two or more
parallel lines
8. A Vertex
A vertex is where two lines meet to form an
angle
5.
Mr McCormack
Geometry Definitions
Congruent Triangles
Congruent triangles are triangles where
all corresponding sides and angles are
equal in measure
10. Similar Triangles
Similar Triangles or equiangular
triangles are triangles that have the
same three angles as the other traingle
9.
Mr McCormack
Circle Definitions
 Chord

A chord is a line that joins any two points on the
circle
 Arc

Any part of the circumference of a circle
 Tangent

A line that cuts/touches a circle at one point
Mr McCormack
exterior
interior
vertically opposite
reflex
obtuse
acute
right angle
parallelogram
corresponding
transversal
alternate
parallel
supplementary
*
perpendicular
angles
theorem
Geometry 1
chord
tangent
point of contact
proof
converse
axiom
circles
corollary
triangles
scalene
perpendicular height
right-angled
congruent
equilateral
equiangular
isosceles
Mr McCormack
similar
corresponding sides
ASA etc.