Bell Work:

Quinn runs a sandwich shop. Since she added a turkey melt to the menu, 36 out of 120 customers have ordered the new sandwich. What is the probability that the next customer will order a turkey melt?

Answer:

3/10

Lesson 60:Area of a

Parallelogram

Recall that to find the area of a rectangle we multiply the length and width, which are the perpendicular dimensions of a rectangle.

x

yArea = xy

Also recall that to find the area of a triangle, we multiply the perpendicular base and height as the first step to calculating the area. Then we find half of that product.

Likewise, to find the area of a parallelogram we multiply the perpendicular base and height. Again, the product is the area of a rectangle, but the area of the rectangle is equal to the area of the parallelogram.

In the figure below, notice that the part of the parallelogram outside the rectangle matches the missing portion of the rectangle.

The formula for the area of a parallelogram is

A = bh

In which A represents area, b represents the length of the base, and h represents the height. Two parallel sides are the bases of a parallelogram. The perpendicular distance between the bases is the height.

Example:

Find the perimeter and area of this parallelogram.

6 cm

8 cm

5 cm

Answer:

P = 8 cm + 8 cm + 6 cm + 6 cm

= 28 cm

A = 8 cm x 5 cm

= 40 cm 2

Practice:

a) On a coordinate plane sketch and find the area of a parallelogram ABCD with vertices A (2, 1), B (1, -1), C (-2, -1), and D (-1, 1).

Answer:

Area = 6 square units

Practice:

b) Graph the dilation of parallelogram ABCD with scale factor 3. What is the area of the image?

Answer:

54 Square Units

Practice:

c) The area of the image is how many times the area of parallelogram ABCD? Why?

Answer:

The area of the image is 9 times the area of parallelogram ABCD because the scale factor tripled the base and tripled the height. Therefore, when we multiply the base and height, the product (the area) is 9 times as great.

HW: Lesson 60 #1-30