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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Selected Reading
- Who is Who
- Computer Glossary
- HR Interview Questions
- Effective Resume Writing
- Questions and Answers
- UPSC IAS Exams Notes
Finding the side length of a rectangle given its perimeter or area
Finding the side length of a rectangle given its perimeter or area
In this lesson, we solve problems where we find one missing side length while one side length and area or perimeter of the rectangle are given.
Determine the value of L .
Perimeter = 22 cm
Solution
Step 1:
Perimeter of a rectangle = 2(l + w); l = length = L; w = width = 6
Step 2:
Perimeter of given rectangle = 2(L + 6) = 22 cm
L + 6 = $frac{22}{2}$ = 11;
So missing length L = 11 – 6 = 5 cm
Determine the value of L .
Perimeter = 20 cm
Solution
Step 1:
Perimeter of a rectangle = 2(l + w); l = length = L; w = width = 7
Step 2:
Perimeter of given rectangle = 2(L + 7) = 20 cm
L + 7 = $frac{20}{2}$ = 10;
So missing length L = 10 – 7 = 3 cm