geometrical concepts Flashcards
1
Q
point
A
- location represented with a dot.
- name with a capital letter e.g A
2
Q
line
A
- set of points that extend forever in two directions.
- two points define a line.
- name with two capital letters- the names of the two points that define the line e.g AB (line on the top)
- name with only one small letter e.g m (line on the top)
3
Q
line segment
A
- parts of a line that has two fixed points, starting and ending point.
- name with two capital letters-the 1st letter is the starting point and the 2nd the ending point e.g AB (line on the top)
4
Q
ray
A
- part of the line that has a fixed starting point and never ends.
- name with two capital letters-the 1st letter is the starting point e.g AB (with an arrow on the top )
5
Q
angle
A
- two rays with common starting point creat and angle
- the rays are called sides or arms of the angle
- the common starting point is called vertex of the angle
- name with 3 capital letters - the middle letter is always the vertex
- name with only 1 capital letter - the vertex
- name with only 1 small letter - the angle
- we always put this symbol ^ on the top or this one < in the beginning.
6
Q
intersecting lines
A
- lines that they have one point in common
7
Q
perpendicular lines
A
- lines that intersect on a right angle
8
Q
parallel lines
A
-lines that never intersect
9
Q
straight angle
A
- 180
10
Q
right angle
A
-90
11
Q
acute angle
A
> 90 (less than a right angle)
12
Q
obtuse angle
A
< 90 ( greater than a right angle)
13
Q
revolution angle
A
one complete turn 360
14
Q
scalene triangle
A
3 sides of different lengths
15
Q
isosceles triangle
A
two sides are equal
