Maths Exam 29 Dec Flashcards
(31 cards)
What is a line
A line is made up of an infinite
number of points that go on forever in both directions. It does not have a beginning
or an endpoint.
What is a straight line
A straight line is the shortest distance
between two points. It can go on infinitely in
both directions.
What is a ray
A ray has one endpoint.
What is a line segment
A line segment has two endpoints.
How does an angle form
When two straight lines meet an
angle is formed.
What is a vertex
The two straight lines are called arms and the point at which they meet is called the vertex.
What is an angle
The rotation of an arm around a point, measured in degrees
What is an acute angle
An angle smaller than 90°
What is a right angle
An angle that is 90°
What is an obtuse angle
It is grater than 90°
What is a straight angle
It is 180°
What is a reflex angle
It’s greater than 180° but smaller than 360°
What is a revolution
Its 360°
If the sum of two angles = 180° they are
Supplementary angles
If the sum of two angles = 90° they are
Complementary angles
What are 2 things that adjacent angles have in common
Adjacent angles are angles that are next
to each other so that they have a
common vertex and a common arm.
When are angles perpendicular
Two lines are said to be perpendicular when they meet at an angle of 90° (a right angle).
How do you multiply decimals by decimals
Remove the decimal commas and multiply the numbers as you would normally (you may need to use long multiplication if the numbers are big). Now count the number of digits after the decimal commas in the question. This will be the number of digits after the decimal comma in the answer.
what MUST you do when dividing decimal fractions
When dividing decimal fractions, the number we are dividing by (the divisor) MUST be made into a whole number. We do this by multiplying BOTH numbers by 10, 100 or 1 000. This won’t change our answer because we are multiplying both numbers by the same amount.
What does Percent mean
Percentage means parts of a hundred.
How do you work out Percentage increase or decrease
Difference 100
```````````````````` × ```````
Original amount 1
What is a ratio
A ratio is a comparison between 2 or more values of the same kind. It is a fraction which is recorded as a ratio.
What is a rate
Rate is when we compare two or more values with different units of measurement.
What is a polygon
A polygon is a two-dimensional shape, enclosed by three or more straight sides.
A triangle is a polygon with three straight sides.
