Formulas
Double Jeopardy
What is the formula for calculating the area of a circle?
Area of Circle = PI x (radius x radius)
DJ
What is another way you can write 1/4 and when should you use it?
0.25, when Pi = 3.14
DJ
Look at the Pie Chart and what the red square tells you about the apples?
That apples represent 1/4
DJ
what is the area of a circle given a radius of 35 m? (Pi = 22/7)AOC = Pi x (radius x radius)
= 22/7 x (35 x 35)
= 22/7 X 1225
= 26950/7
=3850 m2
DJ
Read the Pie Chart and list 4 things you know-
1) 1/2 the shirts sold were L
2) 1/4 of the shirts sold were M
3) Size S and XL sold the same amount
4) The most about of shirts were L
Double Jeopardy
What is the formula for calculating area of a semicircle? Give answer for when PI represents 22/7 and 3.14
Area of Semicircle = 1/2 x PI x (Radius x Radius)ç
&
Area of Semicircle = 0.5 x PI x (Radius x Radius)
When reading a Pie Chart, what should your final answer be if the question reads ¨what fraction of the students liked math?¨
in a fraction
How many people chose football?
40
DJ
What is the area of a circle given its diameter 56 cm? (PI = 22/7)
AOC
Step 1: R = D/2 = 56/2 = 28
Step 2: Pi X (r x r)
= 22/7 x (28 x 28)
= 22/7 X 784
= 17248/7
= 2464 cm2
What clothing item was sold in the greatest quantity?
Shirts (80)
Double Jeopardy
Answers for area must include two things
1. Unit of measurement (i.e. cm, m, etc.)
2. Answers must be squared (2)
DJ
What is another way for writing 0.5 and when should you use it?
1/2 and when PI = 22/7
What percentage of people chose music?
25%
DJ
What is the area of a quadrant given a radius of 28m? (Pi = 22/7)
AOQ = 1/4 x Pi x (radius x radius)
=1/4 x 22/7 x (28 x 28)
= 22/28 x 784/1
= 17248/28
=616 m2
DJ
How many pairs of shoes were sold?
200-80-30-40 = 50
50 pairs of shoes were sold
What is the area of a circle given its diameter?
Area of Circle =
Step 1 = Find the radius - diameter/2
Step 2 = Find the Area - PI x (radius x radius)
When reading a Pie Chart, what should your final answer be if the question reads ¨what percentage of children like video games?¨
Percentage
How many people chose swimming?
20- 12 = 8
DJ
What is the area of a semicircle given a radius of 20 cm? (Pi = 3.14)
AOS = 1/2 x Pi x (radius x radius)
= 0.5 x 3.14 x (20 x 20)
= 1.57 x 400
= 628 cm2
DJ
What fraction of the clothing sold were shirts?
80/200 = 2/5
2/5 of the clothing sold was shirts
Double Jeopardy
What is the area of a quadrant? Give your answer for when PI = 22/7 & 3.14
Area of Quadrant = 1/4 x PI x (Radius x Radius)
&
Area of Quadrant = 0.25 x PI x (Radius x Radius)
When reading a Pie Chart, what should your final answer be if the question reads ¨How many people like to travel?¨
How many people were there in total?
40 + 20 + 12 +8 = 80 people
DJ
what is the area of a circle given a diameter of 84 m? (Pi = 3.14)
AOC = PI x (R x R)
Step 1: R = D/2 = 42
Step 2: 3.14 x ( 42 x 42)
=3.14 x 1764
= 5538.96 m2
DJ
Draw a pie chart showing the following information
1) pencils = 1/2
2) erasers = 1/4
3) paper and book represents the 2 remainder parts and equal the same amount
half the circle is pencils
1/4 is erasers
1/6 is paper and books