Perimeter and Area of Polygons
Selected Reading
- Finding the perimeter or area of a rectangle in the coordinate plane
- Area of a trapezoid
- Area of a parallelogram
- Area involving rectangles and triangles
- Finding the area of a trapezoid on a grid by using triangles and rectangles
- Area of a triangle
- Finding the area of a right triangle or its corresponding rectangle
- Finding the area of a right triangle on a grid
- Area between two rectangles
- Area of a piecewise rectangular figure
- Finding the side length of a rectangle given its perimeter or area
- Word problem involving the area of a square or a rectangle
- Areas of rectangles with the same perimeter
- Distinguishing between the area and perimeter of a rectangle
- Area of a rectangle involving fractions
- Perimeter of a piecewise rectangular figure
- Finding the missing length in a figure
- Sides of polygons having the same perimeter
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- HR Interview Questions
- Effective Resume Writing
- Questions and Answers
- UPSC IAS Exams Notes
Finding the perimeter or area of a rectangle in the coordinate plane
Finding the perimeter or area of a rectangle in the coordinate plane
In this lesson, we are given rectangles in the coordinate plane. We are required to find the perimeters and the areas of these rectangles. We read the coordinates of the vertices of these rectangles and can count the lengths of the sides of the rectangles from the grid.
Once the lengths and widths are knows we can find the perimeters and areas of these rectangles.
Alternatively, we can count the number of unit squares on the grid to find the areas and along the boundary to find the perimeters of the rectangles.
Find the area and perimeter of the following rectangle.
Solution
Step 1:
Area of a rectangle = l × w; l = length = 5; w = width = 4
Step 2:
Perimeter of the rectangle = 5 + 4 + 5 + 4 = 18 units
Area of the rectangle = 5 × 4 = 20 square units.
Find the area and perimeter of the following rectangle.
Solution
Step 1:
Area of a rectangle = l × w; l = length = 7; w = width = 4
Step 2:
Perimeter of the rectangle = 7 + 4 + 7 + 4 = 22 units
Area of the rectangle = 7 × 4 = 28 square units.