Math Problem Statement

There is an octagonal Park as shown in the adjacent figure find its area

There is an octagonal park as shown in the adjacent figure. Find its area.

Solution

To find the area of the octagonal park shown in the image, we can decompose the shape into simpler geometric shapes whose areas we can calculate and then sum.

The decomposition of the octagon is as follows:

  1. Central rectangle: Dimensions are 12m×8m12 \, \text{m} \times 8 \, \text{m}.

    • Area = 12×8=96m212 \times 8 = 96 \, \text{m}^2.
  2. Four trapezoids (on the sides of the rectangle):

    • Each trapezoid has parallel sides 4m4 \, \text{m} and 8m8 \, \text{m}, and height 6m6 \, \text{m}.
    • Area of one trapezoid = 12×(Base1+Base2)×Height\frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height} = 12×(4+8)×6=36m2\frac{1}{2} \times (4 + 8) \times 6 = 36 \, \text{m}^2.
    • Total area of all four trapezoids = 36×4=144m236 \times 4 = 144 \, \text{m}^2.
  3. Two triangles (on the corners):

    • Each triangle is right-angled with legs 4m4 \, \text{m} (height) and 6m6 \, \text{m} (base).
    • Area of one triangle = 12×Base×Height=12×4×6=12m2\frac{1}{2} \times \text{Base} \times \text{Height} = \frac{1}{2} \times 4 \times 6 = 12 \, \text{m}^2.
    • Total area of both triangles = 12×2=24m212 \times 2 = 24 \, \text{m}^2.

Total Area:

Adding up the areas of all the components: Total Area=96+144+24=264m2.\text{Total Area} = 96 + 144 + 24 = 264 \, \text{m}^2.

Thus, the area of the octagonal park is 264m2264 \, \text{m}^2.


Would you like me to break it down further or confirm this with another method?

Related Questions:

  1. How do you calculate the area of a trapezoid in general?
  2. How can we calculate the perimeter of the same octagon?
  3. What if the dimensions were doubled? How would the area scale?
  4. How is this decomposition strategy useful for irregular shapes?
  5. What is the formula for the area of a regular octagon, and how does it differ from this case?

Tip:

For irregular polygons, decomposing them into triangles, rectangles, and trapezoids makes the calculations simpler and more structured.

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Math Problem Analysis

Mathematical Concepts

Geometry
Area of Composite Figures
Trapezoids
Triangles

Formulas

Area of rectangle = length × width
Area of trapezoid = 1/2 × (Base1 + Base2) × Height
Area of triangle = 1/2 × Base × Height

Theorems

Basic area calculation formulas for geometric shapes

Suitable Grade Level

Grades 6-8