Introduction
In this lesson students
practice calculating areas
of different geometric
figures within the context
of a problem-based learning
scenario. They will use
these skills in the M.A.R.S.
mission to make important
decisions concerning the
location of the base.
Duration
30 minutes
Formulas
Area of a rectangle: A = B
× H
B = base
H = height
Area of a triangle: A = B
× H
2
Area of a circle: A = π
× r2
Area of a quadrilateral: A =
B × (H1
+ H2)
2
pi: (π) 3.14
Radius (r): a line extending
from the center of a circle or sphere to the
circumference (outside boundary)
Materials
Procedure
- Review with the students the formulas
for the areas of different geometric
figures.
- Check for understanding of vocabulary
involved in the formulas.
- Read the problem activity that follows
with the class before they begin work.
Problem Activity
You and your school nature club are trying
to raise money for a club field trip to the
Amazon rain forest. You have agreed to landscape
the school grounds and plant flower bulbs to
bloom in the spring.
The school board wants the
bulbs planted in a very specific way so the new
bulbs blend in with the existing landscaping.
They want the largest area
planted with tulips, the next largest area with
daffodils, the third largest area with crocuses,
and the three smallest areas are to be planted
with wildflower bulbs.
There are six areas to be
planted, but you and your club have a problem!
All of the areas are of different sizes and
shapes! You will need to calculate the areas
before you plant the bulbs so you plant the
correct type of bulb in the correct area!
You measure each area to be
planted and now have the following dimensions:
circle |
rectangle |
triangle |
quadrilateral |
r =
3.5 meters |
B = 5
meters
H = 3 meters |
B = 6
meters
H = 2 meters |
B = 2
meters
H1 = 2 meters
H2 = 3 meters |
circle |
triangle |
|
|
r = 5
meters |
B = 4
meters
H = 6 meters |
|
|
Directions
- Calculate the area of each shape to be
landscaped. Use the space below the table to
show your work.
- Complete the following table listing the
area and the type of flower bulb you will
plant in each location. Work carefully! Your
club will not get paid if you are wrong!
Location |
Area (m2) |
Type of Flower Bulb Planted |
Circle #1 |
|
|
Circle #2 |
|
|
Rectangle |
|
|
Triangle #1 |
|
|
Triangle #2 |
|
|
Quadrilateral |
|
|
Answers:
Circle #1 = (3.14)
(12.25)
= 38.465 m2 |
Triangle #1 = 12/2
= 6 m2 |
|
|
Circle #2 = (3.14)
(25)
= 78.5 m2 |
Triangle #2 = 24/2
= 12 m2 |
|
|
Rectangle = (5)
(3)
= 15 m2 |
Quadrilateral =
10/2
= 5 m2 |
Location |
Area (m2) |
Type of Flower Bulb Planted |
Circle #1 |
38.465 |
daffodils |
Circle #2 |
78.5 |
tulips |
Rectangle |
15 |
crocuses |
Triangle #1 |
6 |
wildflowers |
Triangle #2 |
12 |
wildflowers |
Quadrilateral |
5 |
wildflowers |
|