SHAPES AND PATTERNS GRADE 3

Hello, How are you doing? Today, we are going to start a new lesson on Shapes and Patterns.

Triangle A triangle is a polygon having 3 sides and 3 angles. Different type of triangles (on the basis of sides) are –  Equilateral triangle  Isosceles triangle  Scalene triangle

Triangles Different type of triangles on the basis of angle are –  Acute triangle  Right triangle  Obtuse triangle

Equilateral and Isosceles triangle Equilateral triangle – Three sides are of same length. Isosceles triangle – Two sides are of same length. 4 cm 3 cm 6 cm

Scalene triangle Scalene triangle – No side is of same length. 8 cm 3 cm 5 cm

Acute and Right triangle Acute Triangle – All angles are less than right angle. Right Triangle – One angle is right angle.

Obtuse triangle Obtuse triangle – A triangle in which one angle is greater than right angle. 105°

Quadrilateral Quadrilateral is a closed figure with 4 sides and 4 angles. Kind of Quadrilateral  Square  Rectangle  Parallelogram  Rhombus  Trapezoid

Parallelogram and Rhombus Parallelogram – Both pairs of opposite sides are parallel. Rhombus – All the four sides of the same length but no right angle. Parallelogram rhombus

Trapezoid Trapezoid – A quadrilateral with exactly one pair of parallel sides. Trapezoid

Diagonal Lines A diagonal line connects one vertex to another vertex, but not side.

Identify the following. a) It has 4 sides and 4 angles. b) It has 3 sides and one of the angle is right.

Draw the diagonal line of the following Quadrilateral.

a) Acute triangle has one angle greater than right angle. b) Scalene triangle has no side equal. c) Right triangle has two right angles. Say True or False.

Assessment

1.Identify each triangle as acute, obtuse or right. A B C

2.An equilateral triangle has 2 sides of the length 4 cm. What is the length of the third side?

3.Name the following. a) A triangle with no side equal. b) A quadrilateral with exactly one pair of parallel sides.

4.Identify each quadrilateral. A B C

5.Give one point of similarity and dissimilarity in square and rhombus.

6.Complete the table. Number of Quadrilateral Number of sides 2 5 6

7.Which among the following triangle has two sides equal? a) Scalene b) Isosceles c) Equilateral

8.Which statement is correct? a) All polygons are quadrilaterals. b) All Quadrilaterals are polygons. c) All quadrilaterals has 4 sides.

9.Which of the following has opposite sides parallel and equal? a) Parallelogram b) Trapezoid c) rhombus

10.Which word could NOT describe a triangle? a) Plane figure b) Polygon c) Equilateral d) Four sided

Recap Triangles -  Equilateral  Scalene  Isosceles  Right  Acute  Obtuse Quadrilateral –  Rectangle  Rhombus  Square  Trapezoid  parallelogram

Well Done! Now Practice worksheets on the Lesson.