A 2D shape is a shape that is bounded by three or more straight lines or a closed circular line in a plane. These shapes have no depth or height; they have two dimensions- length and breadth and are therefore called 2D figures or shapes. For 2D shapes, we measure area (A) and perimeter (P).

#### Square

A rectangle with four equal sides. Both pair of opposite sides are parallel. Both of its diagonals are equal and cuts at 90 degree.

Both pair of opposite sides are parallel. Both of its diagonals are equal and cuts at 90 degree.

Both pair of opposite sides are parallel. Both of its diagonals are equal and cuts at 90 degree.

Perimeter = 2 * [Side(a) + Side(a)]

Perimeter = 2 * [a + a] = 4a

Area of Rectangle = Side (a) * Side (a)

Area of Rectangle = a * a = a^{2}

#### Rectangle

A quadrilateral with four sides each joining at 90 degree.

Both pair of opposite sides are parallel and equal.

Both of its diagonals are equal

It has a pair of longer sides called Length (L) And a pair of shorter sides called Breadth (B)

Perimeter = 2 * [Length(L) + Breadth(B)]

Perimeter = 2 * [L + B]

Area of Rectangle = Length (L) * Breadth (B)

Area of Rectangle = L * B

**Parallelogram**

A quadrilateral with four sides where both pairs of opposite sides are parallel and equal

Opposite angles are equal (∠A = ∠C & ∠B = ∠D)

Consecutive angles are supplementary –∠A + ∠B = 180 , ∠B + ∠C = 180 ,∠C + ∠D = 180 , ∠D + ∠A = 180

Diagonals of a parallelogram bisects each other

Perimeter = 2 * [Side(a) + Base(b)]

Perimeter = 2 * [a + b]

Area = Base (b) * Height (h)

Area = b * h

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