angles, triangles and polygons

Question 1

x < 90

Answer 1

acute

Question 2

90 < x < 180

Answer 2

obtuse

Question 3

x=90

Answer 3

right

Question 4

180 < x < 360

Answer 4

reflex

Question 5

x + y = 90

Answer 5

complementary

Question 6

x + y = 180

Answer 6

supplementary

Question 7

a + b = 180

Answer 7

adjacent angles on a straight line

Question 8

a + b + c + d + e = 360

Answer 8

angles at a point

Question 9

a = c, b = d (X)

Answer 9

vertically opposite angles

Question 10

a = b (Z)

Answer 10

alternate angles, – // –

Question 11

c = b (F)

Answer 11

corresponding angles, –//–

Question 12

b + d = 180 (C)

Answer 12

interior angles, –//–

Question 13

equilateral triangle

Answer 13

3 equal sides and 3 equal angles

Question 14

isosceles triangle

Answer 14

2 equal sides and 2 equal angles

Question 15

scalene triangle

Answer 15

all sides of different lengths; all angles are different

Question 16

180 in a triangle

Answer 16

angle sum of a triangle

Question 17

exterior = sum of interior opposite angles

Answer 17

exterior angle of a triangle

Question 18

parallelogram

Answer 18

• 2 pairs of equal and parallel opposite sides
• 2 pairs of equal opposite angles
• diagonals bisect each other

Question 19

rectangle

Answer 19

• 2 pairs of equal and parallel opposite sides
• 4 right angles
• diagonals are equal in length and bisect each other

Question 20

rhombus

Answer 20

• 4 equal sides
• opposite sides are parallel
• 2 pairs of equal opposite angles
• diagonals bisect each other at right angles

Question 21

square

Answer 21

• 4 equal sides
• opposite sides are parallel
• 4 right angles
• diagonals are equal in length and bisect each other at right angles

Question 22

kite

Answer 22

• 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

Question 23

trapezium

Answer 23

• 1 pair of parallel sides

Question 24

triangle

Answer 24

3 sided

Question 25

quadrilateral

Answer 25

4 sided

Question 26

pentagon

Answer 26

5 sided

Question 27

hexagon

Answer 27

6 sided

Question 28

heptagon

Answer 28

7 sided

Question 29

octagon

Answer 29

8 sided

Question 30

nonagon

Answer 30

9 sided

Question 31

decagon

Answer 31

10 sided

Question 32

180 (n-2)

Answer 32

sum of interior angles of an n-sided polygon

Question 33

360

Answer 33

sum of exterior angles of any polygon

Question 34

180 (n-2) / n

Answer 34

one interior angle of an n-sided polygon