number cube challenge juanita and clarissa have 4 number cubes and are having fun making up number...
TRANSCRIPT
Number Cube Challenge • Juanita and Clarissa have 4 number cubes and
are having fun making up number games one afternoon.
• Clarissa has an idea for a new game: “Let’s each pick a number you can roll with 2 number cubes. Then we'll each roll 20 times to try to get that number. The person who gets her number the most times wins.”
• “OK,” says Juanita. “I pick the number 12.”• “And I choose 7,” says Clarissa.• Who is more likely to win the game? Why?
• Clarissa is more likely to win because there are more ways to get 7 on the number cubes.
• 1+6 = 7
• 2+5 = 7
• 3+4 = 7
• There is only one combination one the number cubes that will make 12. 6+6.
Number Cube Challenge
Area of Triangles and Trapezoids
Lesson 11-5
5 in
4 in
•What is the area of the parallelogram?
•Area = bxh
•A = 20 in²
•A = 20 in²
•What happened to the parallelogram when we cut it in half?
•We now have two triangles.
•What would the area of one triangle be?????????
•What could we use as a formula to find the area of a triangle?
The area of a triangle is half of the area of a parallelogram.
A = ½ bh
h
b
Triangles
Find the Area of the Triangle
10m
6.5m
•A = ½ bh
•A = ½ (6.5m) x (10m)
•A = ½ (65m)
•A = 32.5 m²
Find the Area of the Triangle
11ft
14ft•A = ½ bh
•A = ½ (14ft) x (11ft)
•A = ½ (154ft)
•A = 77 ft²
Find the Area of the Triangle
9.6mm
8mm
•A = ½ bh
•A = ½ (8mm) x (9.6mm)
•A = ½ (76.8mm)
•A = 38.4 mm²
Trapezoids
•A trapezoid has two bases, b and b . The height (h) of a trapezoid is the distance between the bases.
•A = ½ h( b + b )
1 2
b 1
b 2
h
1 2
Find the Area of the Trapezoid
5 in
12 in
7 in
•A = ½ h( b + b )
•A = ½ (7in)(5in +12in)
•A = ½ (7in)(17in)
•A = ½ (119in)
•A = 59.5 in²
1 2
Find the Area of the Trapezoid7 ft
15.6 ft
8 ft
•A = ½ h( b + b )
•A = ½ (8ft)(7ft +15.6ft)
•A = ½ (8ft)(22.6ft)
•A = ½ (180.8ft)
•A = 90.4 ft²
1 2
The area of a triangle is half of the area of a parallelogram.
A = ½ bh
h
b
Triangles
Trapezoids
•A trapezoid has two bases, b and b . The height (h) of a trapezoid is the distance between the bases.
•A = ½ h( b + b )
1 2
b 1
b 2
h
1 2
Don’t Forget
• Homework: Lesson 11-5 # 2-14 evens