4th Maths : Term 1 Unit 1 : Geometry
Draw 2D shapes in free hand with geometry tools
Quadrilateral
1. All closed four sided figures are called quadrilaterals
2. It has four sides (AB,BC,CD,DA), four vertices (A,B,C,D) and two diagonals (AC,BD)
EXAMPLES
Square, Rhombus, Rectangle, Trapezium, Parallelogram
Square, Rhombus, Rectangle, Trapezium, Parallelogram
Square
A square has four equal sides (PQ=QR=RS=SP), four vertices (P, Q, R, S) and two diagonals (PR, QS).
The diagonals of a square are equal in length (PR = QS).
Examples
Carom board, Chess board, One face of the dice
Carom board, Chess board, One face of the dice
Rectangle
A rectangle has four sides (WX, XY, YZ, ZW) and four vertices (W, X, Y, Z). It has two equal diagonals (WY = ZX) and opposite sides are equal (WX = YZ ; XY = WZ).
Examples
Mat, Black Board
Mat, Black Board
Rhombus
A rhombus has four equal sides (LM = MN = NO = OL), four vertices (L, M, N, O) and two diagonals (LN, MO).
The diagonals are not equal in length.
Examples
Parallelogram
A Parallelogram has four sides (EF, FG, GH, HE) and four vertices (E, F, G, H). Opposite sides are parallel and equal in length (EF=GH; FG=HE)
Activity
Use Geoboard and rubber band to form or deform or reform the different shapes. Discuss similarities and differences among the shapes.