# Perimeter and Area of Rectangles, Squares and Triangles

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Perimeter and Area of Rectangles, Squares and Triangles

Warm Up What do you already know? List the formulas for perimeter or area for the following polygons?

Polygon Activity On the graph paper provided, complete the following steps: Using a ruler, draw the x and y- axis of a coordinate plane on your graph paper. Draw three polygons on your graph paper, in any quadrant– a square, a rectangle and a right triangle (be sure that the height of each polygon is at least 6 units). Label the coordinate points (x, y) for each point of your polygons.

Finding Perimeter Find the perimeter of each of your three polygons units. (You may use a second piece of graph paper to measure the number of units when a polygon’s side does not match the lines on the graph paper.) Find the length of sides in two ways: Count the number of square units Use a formula for distance when applicable

Formulas Perimeter – the distance around the outside of the polygon Perimeter of a rectangle p = 2l + 2w or p = 2(l+w) Area Of a Square/Rectangle = length x width A = lw or A = bh Of a triangle = (base x height) ÷ 2 or

Base & Height What is the base of a triangle?
The base must form a right angle with the height. How do we decide which measures are the base and the height? The two measures that form a right angle on or in the polygon.

Parallelograms On the graph paper provided, complete the following steps: Using a ruler, draw the x and y- axis of a coordinate plane on your graph paper. Draw the quadrilateral with the following vertices: (1,7), (7,7), (10,2), (4,2). Use a straight edge to connect the points. Carefully cut out your figure and see if you can find the area in square units. Day 2: Parallelograms

Were there things that stayed the same? Can we put that information into a formula to find the area of any parallelogram? Area of a Parallelogram: A = bh

Warm Up What is the formula for the area of a parallelogram?
Complete Igor #2 and #6 for area. Draw the figure in your journal.

Skill Check All lengths are listed in cm. Show correct UNITS!!!!!!
Find the perimeter and area of the parallelogram. Find the perimeter and area of the triangle. 12 10 8 6 6 7 6

Review of Area 1. What is the formula for the area of each of the following: Square Rectangle Triangle 2. Draw a parallelogram. What is the formula for its area?

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