Math Flashcards
(21 cards)
How to find the perimeter of a triangle
Add all sides together
P = a + b + c
How to find the area of a triangle
Find half of the base times height
A = 1/2 (b x h)
How to find the perimeter of a quadrilateral
Add all the sides together
What is a quadrilateral?
Figure with 4 sides
Ex: rectangle, parallelogram, rhombus, square, trapezoid
What is a parallelogram?
Quadrilateral with opposite sides that are parallel and equal in length
What is a rectangle?
A parallelogram where all 4 sides from right angles (90 degrees)
What is a rhombus?
A parallelogram where all sides are equal in length
What is a square?
A parallelogram where all sides are equal in length and form right angles
What is a trapezoid?
A quadrilateral with only 2 parallel sides, sides do NOT have to be the same length
How do you find the area of a parallelogram?
Multiply base and height
A = bh
How do you find the circumference of a circle using the radius?
Multiply the radius and pi (3.14) and then double it (x 2)
C = 2( pi x r)
How do you find the circumference of a circle using the diameter?
Multiply the diameter by pi (3.14)
C = pi x d
How do you calculate tax?
Change the percentage to a decimal and then multiply with the price
Tax = 20%
Price = $100
20% —> 0.2
0.2 x $100 = $20
How do you find the volume of a rectangular solid?
Multiply length, width, and height
V = lwh
What does a ratio tell you?
How the quantity of 2 different things compares
How do you write a ratio?
There are 5 blue marbles and 10 red marbles? What is the ratio of blue to red marbles?
5:10 5/10 —> reduces to 1/2
How do you read a ratio?
The ratio of cars to trucks is 2:3
There are 2 cars for every 3 trucks
How do you reduce 25/75
Find the greatest common factor of 25 and 75 and then divide each side by that denominator.
GCF of 25 and 75 is 25
25 / 25 = 1
75 / 25 = 3
25/75 —> 1/3
How do you reduce mixed numbers?
Reduce 2 8/20?
Convert the mixed number to an improper fraction, find the greatest common factor, and divide both sides, the convert back ti a mixed number if needed.
2 8/20 —> 48/20
GCF of 48 and 20 is 4
48 / 4 = 12
20 / 4 = 5
48/20 —> 12/5
12/5 —> 2 2/5
How do you change a percentage to a decimal?
Change 52% to a decimal
You divide by 100
52/100 —> 0.52
How do you change a percentage to a fraction?
Change 52% to a fraction
Put the percentage over 100 and simplify.
52/100
GCF is 4
52 / 4 = 13
100 / 4 = 25
52/100 —> 13/25
