What Shape Has 4 Sides and 3 Corners

2-D FIGURES!!

3-D FIGURES!!

TRIANGLES!!

POLYGONS!!

QUADRILATERALS!!

Quadrilaterals

A quadrilateral is a closed figure with 4 sides. Some shapes that are classified as quadrilaterals are square, rectangle, parallelogram, rhombus, and trapezoid. We will learn more about these shapes in the next few pages. These are 2-D shapes.

This is a square. It has 4 right angles and 4 equal sides. It has 4 sides and 4 vertices. Its angles are 90 degrees.

This is a rectangle. It has 4 right angles and the opposite sides are equal. It has 4 sides and 4 vertices. Its angles are 90 degrees.

This is a parallelogram. A parallelogram has both pairs of opposite sides that are parallel. It has 4 sides and 4 vertices. 2 of its angles are more than 90 degrees or obtuse and 2 of its angles are less than 90 degrees, or acute.

This is a rhombus. It has 4 sides the same length and no right angles. It has 4 sides and 4 vertices. 2 of its angles are more than 90 degrees or obtuse and 2 of its angles are less than 90 degrees, or acute.

This is a trapezoid. It has exactly one pair of parallel sides. It has 4 sides and 4 vertices. 2 of its angles are more than 90 degrees, or obtuse and 2 of its angles are less than 90 degrees, or acute.

Now it's your turn. Take out a piece of paper and pencil and practice drawing the shapes.

Now we will move on to triangles. All triangles have 3 edges and 3 vertices. The most common types of triangles are, right triangles, acute triangles, and obtuse triangles.

This is a right triangle. One of its angles is a right angle, or 90 degrees. It has 3 sides and 3 vertices.

This is an acute triangle. All the angles are less than a right angle, or less than 90 degrees. It has 3 sides and 3 vertices.

This is an obtuse triangle. One of the angles is greater than a right angle, or greater than 90 degrees. It has 3 sides and 3 vertices.

Now why don't you practice drawing these triangles. Remember a right triangle has one 90 degree or right angle, an acute triangle has all angles less than 90 degrees, or less than a right angle, and an obtuse triangle has one angle greater than 90 degrees or greater than a right angle.

Now lets learn about polygons. A polygon is a closed figure with straight edges. The most common polygons are pentagon, hexagon, and octagon.

These are pentagons. A pentagon has 5 angles, 5 sides and 5 vertices.

This is a hexagon. A hexagon has 6 angles, 6 sides and 6 vertices.

This is an octagon. An octagon has 8 angles, 8 sides, and 8 vertices. An octagon looks just like a stop sign.

Now lets learn about 3-D figures. A 3-dimensional figure is a figure that has length, width, and height.

This is a cube. It has 6 faces, 12 edges, and 8 vertices.

This is a rectangular prism. A rectangular prism has 6 faces, 12 edges, and 8 vertices. It has exactly the same amount of faces, edges, and vertices as a square.