Page 188 - New Medley 4 Semester 2 PDF (Merged)

Yes, the boundary of the park is the sum of lengths of all its edges, i.e.,
120 m + 70 m + 60 m + 50 m = 300 m.

The distance covered in going round the park is called the perimeter.

The perimeter is the total length of the boundary which forms a closed
figure.

We know that polygons are simple closed curves made up of line segments.
Such polygons are also called rectilinear figures.

Triangles, rectangles, squares, etc., are rectilinear figures.

Perimeter of a rectilinear figure = Sum of all its sides
A
Therefore, Perimeter of a triangle ABC

= AB + BC + AC

Perimeter of a rectangle ABCD
B C
= AB + BC + CD + DA

= AB + BC + AB + BC ( AB = DC and BC = AD)

= 2AB + 2BC = 2(AB + BC)
A B

Also, we can say, the perimeter of a rectangle

= 2(length + breadth)

Perimeter of a square ABCD D C

= AB + BC + CD + DA

= AB + AB + AB + AB ( AB = BC = CD = DA)

= 4 × AB A B

i.e., the perimeter of a square = 4 (side)

D C

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