11.1 Area of Triangles & Parallelograms

HW pg. 723 #4­26 evens 1

March 06, 2013

Jan 22­1:56 PM

11.1 Areas of Triangles & ParallelogramsObjectives: 1. To develop the concept of area.2. Apply area formulas to solve problems.

Formula for:Area of a Rectangle: A = bh

The base and height are always perpendicular to each other.

What is area?

Rules for Using Formulas:1. Always state the formula you are using first!2. Identify the knowns & unknowns for each variable in the formula.3. Plug the knowns into the equation.4. Solve for the unknown using algebra.5. Be sure to include a label with your answer.

A = _____

10.5m22m

Find the area of the rectangle:

11.1 Area of Triangles & Parallelograms

HW pg. 723 #4­26 evens 2

March 06, 2013

Jan 18­2:48 PM

6m12m

20m

Area of a Parallelogram: A = bhThe altitude will be perpendicular to the base.

A = _____Find the area of the parallelogram:

11.1 Area of Triangles & Parallelograms

HW pg. 723 #4­26 evens 3

March 06, 2013

Jan 23­12:14 PM

Area of a Triangle =  1/2bh

h

b

Find perimeter and area of the triangle.

817

10

21

P = 48 unitsA = 84 units2

Base & height are always perpendicular to each other!

Triangles can have multiple appearances:

11.1 Area of Triangles & Parallelograms

HW pg. 723 #4­26 evens 4

March 06, 2013

Jan 23­12:23 PM

Find the height of the parallelogram.

x

20 m

Area = 100 m2

Find the area of the rectangle.

18 m

y

Perimeter = 50 m

11.1 Area of Triangles & Parallelograms

HW pg. 723 #4­26 evens 5

March 06, 2013

Jan 18­3:02 PM

Find the area and perimeter of the shaded region.

18m

15m

10m

9m 8cm

6cm

3cm

1cm

5cm

11cm

P = 66 mA = 222 m2

P = 38 cmA = 77 cm2

11.1 Area of Triangles & Parallelograms

HW pg. 723 #4­26 evens 6

March 06, 2013

Jan 22­8:31 AM

HW:

11.1 pg. 723 #4-26 evens