Perimeter
Perimeter is not only related to the geometrical things but in our daily life also sometime we have to know the perimeter. So what is this perimeter?
Contents
Perimeter is the length of the path of any object in two dimension or it is the outline of that object.
It is measured in meter.
For example:
- We have to guard our yard by iron wire then first we have to know the required length of the iron wire accordingly the dimensions of yard. So this is nothing but the perimeter of the yard.
- The two dimensional objects are having perimeter while the 3D objects possess surface area.
- In case of circle the perimeter means the circumference of circle while in case of any quadrilateral perimeter means the sum of length of all its sides. Hence, we can determine the perimeter of any object in two dimension.
- Below is the some geometrical figure is given and we have to find its perimeter. Then only we have to take the sum of length of its all sides simply.
Following are the some geometrical shapes and their formulae for perimeter:
1.) Rectangle:
- The rectangle is the quadrilateral in which opposite sides are equal and has 4 right angles at its four corners.
- Here we have to find the perimeter of rectangle that means we have to find the length of red line which is the outline of rectangle here.
- If a is the length and b is the breadth of rectangle then its perimeter is given by,
- Perimeter of rectangle = 2* (a + b)
2.) Square:
- Square is the rectangle whose all sides are equal in length.
- To find the perimeter of square we have to add the length of its side 4 times only.
- If a is the length of side of square then its perimeter is given by,
- Perimeter of square = 4* side of square = 4*a
3.) Circle:
- Circle is the locus of points which are at a fixed distance from the centre point called as centre of circle.
- The perimeter of circle means the circumference of the circle.
- To find the circumference of circle we have to know only the radius of the circle.
- If r is the radius of circle then its perimeter is given by,
- Perimeter of circle = 2*π* r
4.) Semicircle:
- The semicircle means the half circle.
- If r is the radius of circle then the perimeter of semicircle is given by,
- Perimeter of semicircle= π*r
5.) Triangle:
- Triangle is the geometrical shape having three sides and three angles as shown in figure.
- To find its perimeter we have to add only all its sides length.
- If a, b, c are the lengths of given triangle then its perimeter is given by,
- Perimeter of triangle = a + b + c
6.) Equilateral triangle:
- Equilateral triangle is the triangle whose all three sides are equal and each internal angle measures as 600.
- To find the perimeter of equilateral triangle we have to know only the length of one side of equilateral triangle.
- If a is the length of one side of equilateral triangle then its perimeter is given by,
- Perimeter of equilateral triangle = 3* a
7.) Isosceles triangle:
- Isosceles triangle is the triangle whose two sides are equal in length and third is different from them.
- And also the internal angles opposite to the equal sides are equal.
- To find the perimeter of isosceles triangle we have to know the length of same sides and length of third different side.
- If a is the length of equal sides and b is the length of third side then the perimeter of isosceles triangle is given by,
- Perimeter of isosceles triangle = 2*a + b
8) Parallelogram:
- Parallelogram is the quadrilateral with opposite sides are parallel and equal.
- The opposite angles in parallelogram are also equal and the adjacent angles sums to form the 1800.
- Here in parallelogram ABCD, AB ‖ DC, AD ‖ BC and AB=DC, AD=BC.
- Also, <D = <B, <A = <C and <A + <B = 1800, <D + <C = 1800.
- And the diagonals of parallelogram bisects each other.
- If AB=DC= a and AD = BC = b then the perimeter of parallelogram is given by
- Perimeter of parallelogram = 2* (a + b)
9.) Rhombus:
- Rhombus is the special type of parallelogram in which all sides are equal in length.
- If a is the length of one side of rhombus then its perimeter is given by,
- Perimeter of rhombus = 4* a
10.) Trapezoid:
- Trapezoid is the quadrilateral with at least one pair of sides is parallel.
- And all sides are different in length of trapezoid.
- If the side lengths are a, b, c and d then the perimeter of trapezoid is given by,
- Perimeter of trapezoid = a + b + c + d
11.) Regular hexagon:
- The hexagon is the polygon with 6 sides, and its perimeter is the sum of all its six sides.
- But if the hexagon is the regular hexagon which is having all sides equal in length.
- If a is the length of one side of regular hexagon then its perimeter is given by,
- Perimeter of regular hexagon = 6* a
12.) Regular pentagon:
- Regular pentagon is the polygon with 5 sides and all these five sides are equal in length.
- If a is the length of one side of regular pentagon then its perimeter is given by,
- Perimeter of regular pentagon = 5* a