2nd Grade Math
Shapes & Figures
Unit 1
2 Dimensional vs. 3 Dimensional Objects
We can put shapes into two different categories: two-dimensional and three-dimensional. What is the difference between a two-dimensional object and a three dimensional object? Let's Explore!
2-Dimensional Object
Only have two dimensions: length and width
These objects appear to be flat
3-Dimensional Object
Only have three dimensions: length, width, and height
These objects "pop" off the page
Triangles
A triangle is a shape with THREE sides
There are three different types of triangles: Equilateral, Isosceles, and Scalene.
How can we describe triangles?
We can describe triangles by their side lengths. All triangles have three sides that connect. Some sides may be longer, other sides may be smaller. Let's take a look at the three different types of triangles.
Equilateral
All three sides have equal lengths
Isosceles
TWO sides have equal lengths
Scalene
NONE of the sides have equal lengths
What is a Congruence Mark?
A congruence marks are small ticks that are used to show that sides are the same length.
Activity Time:
Click the link to go to triangle worksheet
Classify the triangles by their sides (Equilateral, Isosceles, Scalene)
Check your answers on the second page :)
Link: https://www.mathworksheets4kids.com/triangles/classifying/customary/sides-numerals-1.pdf
Quadrilaterals
A quadrilateral is a shape with 4 sides and 4 angles.
Look at a few examples below!
Rectangle
Two pairs of sides have equal lengths and all 4 angles are equal!
Square
Like a rectangle except all four sides have equal lengths!
Rhombus
Like a square (all sides have equal lengths) but not all angles are equal!
Trapezoid
Only 1 pair of parallel lines with 4 angles (not always equal)!
Pentagon
5 Sides
Hexagon
6 Sides
Octagon
8 Sides
Watch these videos to learn more about 2D shapes
3 Dimensional Objects
In this section we are going to be focusing on 6 different 3D figures:
cones, rectangular prisms, spheres, pyramid, cube, and cylinders.
Cone
Sphere
Cylinder
Pyramid
Cube
