Angles, lines and polygons

Question 1

What angle is a full turn?

Answer 1

360°

Question 2

What angle is a half turn?

Answer 2

180°

Question 3

What angle is a right angle?

Answer 3

90°

Question 4

What is an obtuse angle?

Answer 4

(90°, 180°)

Question 5

What is an acute angle?

Answer 5

(0°, 90°)

Question 6

What is a reflex angle?

Answer 6

(180°, 360°)

Question 7

If two straight lines pass through each other and you know one angle is a°, what are the other angles?

Answer 7

The angle opposite will also be a°. Then, to find the other angles, you can do 180° - a° to know both of the other angles.

Question 8

If a line passes through a set of parallel lines, and we say the angles around each intersection is a, b, c, d, e, f, g, h from top to bottom, and we know the value of a, how do we find the other angles?

Answer 8

a = e which in turn means that a = d = h = e. Then, we can say that b = 180° - a. Therefore overall we can state that a = d = e = h and 180° - a = b = c = f = g.

Question 9

What is an Equilateral triangle?

Answer 9

A triangle with three equal sides and three 60° angles.

Question 10

What is an Isosceles triangle?

Answer 10

A triangle with two equal sides and two equal angles.

Question 11

What is a Right-angled triangle?

Answer 11

A triangle with a right angle.

Question 12

What is a Scalene triangle?

Answer 12

A triangle that isn’t Isosceles.

Question 13

What do all the angles in triangles add up to?

Answer 13

180°, because if you draw a line parallel to the base of the triangle at the top, then the parallel line laws state that the angles in a triangle must add up to 180°.

Question 14

What is a square?

Answer 14

A quadrilateral that has four equal sides and four 90° angles.

Question 15

What is a rectangle?

Answer 15

A quadrilateral that has four 90° angles.

Question 16

What is a rhombus?

Answer 16

A quadrilateral that has four equal sides.

Question 17

What is a parallelogram?

Answer 17

A quadrilateral that has two pairs parallel lines.

Question 18

What is a trapezium?

Answer 18

A quadrilateral that has one pair of parallel lines.

Question 19

What is a kite?

Answer 19

A quadrilateral that is not a square, but has diagonals that bisect at right angles.

Question 20

What is a polygon?

Answer 20

A straight lines, closed, 2D shape with at least three sides.

Question 21

What is a regular polygon?

Answer 21

A polygon with equal sides and equal angles.

Question 22

What is an irregular polygon?

Answer 22

A polygon that isn’t regular.

Question 23

How can you find what the sum of the interior angles of a polygon should be?

Answer 23

By splitting the shape into triangles and seeing how many make up the whole shape. Then, multiply 180° by the number of triangles.

Question 24

What do the exterior angles of a polygon always add up to?

Answer 24

360°

Question 25

What is a line of symmetry?

Answer 25

When the shape can be folded along that line and all of the edges match up.

Question 26

In a regular polygon, what is the rule for the rotational symmetry?

Answer 26

The number of lines of symmetry equal the number of sides.

Question 27

What is rotational symmetry?

Answer 27

If it can be rotated and still look the same.

Question 28

What is the rule for the order of rotational symmetry in a regular polygon?

Answer 28

The order of rotational symmetry equals the number of sides.