Question

What are the areas and perimeters of the following shapes - Rectangle Square Triangle Parallelogram Circle Rohumbus Trapezium

Answer 1

ANSWER

1.) Rectangle

• Area = (Length × Breadth) sq units.

• Perimeter = 2(Length + Breadth)

• Diagonal = √Length² + Breadth²

• Length = Area/breadth

• Breadth = Area/length

2.) Square

• Area = a² or side² sq units.

• Perimeter = 4 × Side or sum of all sides.

• Area = {1/2 × Diagonal²} sq units

• Diagonal = √2side units

3.) Triangle

• Area = (1/2 × Base × Height) sq units

• Perimeter = Sum of all sides or 3 × Side

• Heron's formula = Let a , b , c be the sides of a ∆ABC. Then ,

s = 1/2(a + b + c) is called it's Semi-perimeter.

ar(∆ABC) = √s(s – a)(s – b) (s – c)

4.) Parallelogram

• Area = (Base × Height) sq units

• Perimeter = 2(Length + Breadth) or Sum of all sides.

5.) Circle

• Circumference = 2πr

• Area = πr²

[ For semicircle ]

• Perimeter = (πr + 2r)

• Area = πr²/2

6.) Rhombus

• Area = 1/2 × diagonal (1st) × diagonal(2nd)

• Perimeter = 4 × side or Sum of all sides.

7.) Trapezium

• Area = 1/2 × sum of parallel sides × distance between them.

Also remember these

a.) Equilateral triangle

• Area = √3/4 × side²

• Perimeter = 3 × side or sum of all sides

• Height = √3/2 × side

b.) Isosceles triangle

• Area = (1/4b √4a² – b²) sq units.

• Height = (√4a² – b²/2) units

• Perimeter = (2a + b) units or Sum of all sides.

{ Here in isosceles ∆ABC , AB = AC = a and BC = b }

Answer 2

Answer:

*Rectangle area is :L×B

". ". perimeter:2×(L+B)

* Area of square: Base×Height

perimeter of ". : 4× side

*Area of Triangle:A=1/2×b × h

perimeter of """. : a+b+c

b-----> base

h-----> height

a-----> side

c----->side

*Area of parallelogram: b×h

perimeter of ". : 2×(Side×base)

*Area of circle:πr^2

perimeter of " : 2πr

*Area of Rohumbus:pq/2

perimeter of. ". : 4×Side

*Area of trapezium :a+b/2^h

perimeter of. ". : a+b+c+d

Hope it's help you