angles, triangles and polygons Flashcards
1
Q
x < 90
A
acute
2
Q
90 < x < 180
A
obtuse
3
Q
x=90
A
right
4
Q
180 < x < 360
A
reflex
5
Q
x + y = 90
A
complementary
6
Q
x + y = 180
A
supplementary
7
Q
a + b = 180
A
adjacent angles on a straight line
8
Q
a + b + c + d + e = 360
A
angles at a point
9
Q
a = c, b = d (X)
A
vertically opposite angles
10
Q
a = b (Z)
A
alternate angles, – // –
11
Q
c = b (F)
A
corresponding angles, –//–
12
Q
b + d = 180 (C)
A
interior angles, –//–
13
Q
equilateral triangle
A
3 equal sides and 3 equal angles
14
Q
isosceles triangle
A
2 equal sides and 2 equal angles
15
Q
scalene triangle
A
all sides of different lengths; all angles are different
16
Q
180 in a triangle
A
angle sum of a triangle
17
Q
exterior = sum of interior opposite angles
A
exterior angle of a triangle
18
Q
parallelogram
A
- 2 pairs of equal and parallel opposite sides
- 2 pairs of equal opposite angles
- diagonals bisect each other
19
Q
rectangle
A
- 2 pairs of equal and parallel opposite sides
- 4 right angles
- diagonals are equal in length and bisect each other
20
Q
rhombus
A
- 4 equal sides
- opposite sides are parallel
- 2 pairs of equal opposite angles
- diagonals bisect each other at right angles
21
Q
square
A
- 4 equal sides
- opposite sides are parallel
- 4 right angles
- diagonals are equal in length and bisect each other at right angles
22
Q
kite
A
- 2 pairs of equal adjacent sides
- opposite angles are equal
- one diagonal bisects the other diagonal at right angles
- one diagonal bisects a pair of opposite angles
23
Q
trapezium
A
- 1 pair of parallel sides
24
Q
triangle
A
3 sided
25
quadrilateral
4 sided
26
pentagon
5 sided
27
hexagon
6 sided
28
heptagon
7 sided
29
octagon
8 sided
30
nonagon
9 sided
31
decagon
10 sided
32
180 (n-2)
sum of interior angles of an n-sided polygon
33
360
sum of exterior angles of any polygon
34
180 (n-2) / n
one interior angle of an n-sided polygon
