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Lesson Plan #45
Class: Geometry
Date: Monday December 17th, 2012
Topic: Perimeter and Area
Aim: How can we find the perimeter and area of geometric figures?
Objectives:
1) Students will be able to find the perimeter and area of geometric figures.
HW #45:
Page 426 #’s 17, 18, 24, 29, 32
Page 431 #’s 3, 4, 5
Page 437 # 10, 11
Do Now
Find the area and perimeter of the rectangle at right.
What is the formula for the area of the rectangle?
What is the formula for the perimeter of the rectangle?
What is the area of the triangle at lower right of rectangle?
What is the formula for the area of a triangle?
What is the area of the square?
What is the formula for the area of a square?
What is the area of the circle?
What is the formula for the area of a circle?
PROCEDURE:
Write the Aim and Do Now
Get students working!
Take attendance
Give Back HW
Collect HW
Go over the Do Now
Assignment #1:
Develop a formula for the area of a parallelogram by using the diagram at right.
Find the area of a parallelogram with a base of 12 centimeters and a height of 5 centimeters.
Assignment #2: A rhombus is a parallelogram therefore you can use the same formula
as the formula for the area of a parallelogram to find the area of a rhombus. But you can also use a
different formula. Show why the area of the rhombus at right is given by the indicated formula.
Find the area of a rhombus with diagonals of length 12 and 17
Assignment #3:
Show why the area of the trapezoid at right is given by the indicated formula
Find the area of a trapezoid with bases of 9 centimeters and 7 centimeters, and a height of 3
centimeters
***If the median length is m, and the altitude h, the area of the trapezoid is
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Another way to find the area of a trapezoid is to treat it as some simpler shapes, and then add or subtract their areas
to find the result. For example, a trapezoid could be considered to be a smaller rectangle plus two right triangles:
Sample Test Question:
Find the area of trapezoid REMN
Sample Test Question:
The area of a trapezoid is 52 square inches and the bases are 11 inches and 15 inches. Find the height.
Sample Test Question:
Sample Test Question:
Sample Test Questions: Find the perimeter of the shaded region
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Assignment #4:
Assignment #5:
Assignment #6:
Assignment #7: