Triangles and quadrilaterals: Grade 3 free printable worksheets

As we know, many triangles and quadrilaterals depend on their sides and angles. With this in mind, you must be wondering how to identify these triangles and quadrilaterals easily. Border no more! Mathskills4kids.com will provide the best guide with examples to help your 3^rd Grade students learn to identify accurately and quickly.

Triangles

• Equilateral triangle: A triangle with three equal sides and three equal angles of 60 degrees each. Example: A slice of pizza.
• Isosceles triangle: A triangle with two equal sides and two equal angles opposite them. Example: The roof of a house.
• Scalene triangle: A triangle with no equal sides and no equal angles. Example: A guitar pick.
• Right triangle: A triangle with one right angle of 90 degrees. Example: A corner of a book.
• Acute triangle: A triangle with all angles less than 90 degrees. Example: A slice of pie.
• Obtuse triangle: A triangle with one angle of more than 90 degrees. Example: A sail of a boat.

Quadrilaterals

• Square: A quadrilateral with four equal sides and four right angles. Example: A chessboard.
• Rectangle: A quadrilateral with two pairs of equal sides and four right angles. Example: A sheet of paper.
• Rhombus: A quadrilateral with four equal sides and opposite angles equal. Example: A diamond shape.
• Parallelogram: A quadrilateral with two pairs of parallel sides and opposite angles equal. Example: A tilted square.
• Trapezoid: A quadrilateral with one pair of parallel sides. Example: A trapeze.
• Kite: A quadrilateral with two pairs of adjacent sides equal and one pair of opposite angles equal. Example: A kite.

In this article, you will realize many fun facts about triangles and quadrilaterals that your 3^rd graders will enjoy while learning. Some of these fantastic properties and facts include:

• The sum of the angles in any triangle is always 180 degrees, no matter what type of triangle it is. This is called the angle sum property of triangles.
• The sum of the angles in any quadrilateral is always 360 degrees, regardless of type. This is called the angle sum property of quadrilaterals.
• There is a special type of triangle called an equiangular triangle, which has three equal angles of 60 degrees each. This is also an equilateral triangle because all equiangular triangles are equilateral triangles.
• A special type of quadrilateral called a square has four equal sides and four right angles. This is also a rectangle, a rhombus, and a parallelogram because all squares are rectangles, rhombuses, and parallelograms.
• Pythagoras’ theorem is a theorem that states that in any right triangle, the square of the longest side (called the hypotenuse) equals the sum of the squares of the other two sides (called the legs). This is a very useful theorem for finding missing lengths in right triangles.
• There is a formula called the area formula, which tells you how to find the area of any triangle or quadrilateral. The area is the amount of space inside the shape. The formula differs for different triangles and quadrilaterals, but it usually involves multiplying some lengths and dividing by 2.

One way to classify triangles is by their sides. There are three types of triangles based on their sides: equilateral, isosceles, and scalene.

Another way to classify triangles is by their angles. There are four types of triangles based on their angles: right, acute, obtuse, and equiangular.

Also, our triangle or quadrilateral: Grade 3 free printable worksheets include a part where you can teach your 3^rd graders to combine these two (sides and angles) ways to classify triangles. For example, they can have a right isosceles triangle with one right angle and two equal sides. Or they can have an acute scalene triangle with all angles less than 90 degrees and no equal sides.

Here is a table that shows all the possible combinations of triangles by sides and angles:

Drawing triangles and quadrilaterals can be easy and fun with simple steps and tips. However, we will provide a step-by-step tutorial with tips and tricks that you can use to teach your Grade 3 students how to draw triangles and quadrilaterals easily and accurately. Let’s get started:

How to Draw an Equilateral Triangle

1. Draw a straight line with a ruler. This will be one side of the triangle.
2. Use a protractor to measure 60 degrees from one end of the line. Mark the point where the protractor meets the line.
3. Draw another straight line from that point to the other end of the first line. This will be another side of the triangle.
4. Use the protractor again to measure 60 degrees from the other end of the first line. Mark the point where the protractor meets the second line.
5. Draw another straight line from that point to the end of the second line. This will be the third side of the triangle.
6. You have drawn an equilateral triangle!

Tip: Your 3^rd graders can also use a compass to draw an equilateral triangle. Teach them to draw a circle with any radius and then draw three points on the circle that are equally spaced apart. Ask them to connect these points with straight lines, and they’ll have an equilateral triangle!

How to draw a square

1. Draw a straight line with a ruler. This will be on one side of the square.
2. Use a protractor to measure 90 degrees from one end of the line. Mark the point where the protractor meets the line.
3. Draw another straight line from that point, the same length as the first line. This will be another side of the square.
4. Use the protractor again to measure 90 degrees from the other end of the first line. Mark the point where the protractor meets the second line.
5. Draw another straight line from that point, the same length as the first line. This will be another side of the square.
6. Use the protractor again to measure 90 degrees from the other end of the second line. Mark the point where the protractor meets the third line.
7. Draw another straight line from that point, the same length as the first line. This will be the fourth side of the square.
8. You have drawn a square!

Tip: Your 3^rd graders can also use a compass to draw a square. Ask them to draw a circle with any radius and then draw four points on the circle that are equally spaced apart. Connect these points with straight lines, and they’ll have a square!

3^rd Grade students might think that triangles and quadrilaterals are just shapes they learn in math class, but they are beneficial in real life too! Here are some examples of using these shapes in everyday situations and activities.

• Triangles are often used to make strong structures, such as bridges, roofs, towers, and tents. This is because triangles have a property called rigidity, meaning they do not change shape when you apply force. Ask your students if they can find some examples of triangles in the buildings or objects around you.
• Quadrilaterals are also used to make many things, such as boxes, books, windows, doors, screens, and tiles. This is because quadrilaterals can easily fit together and cover much space. Ask your children if they can think of other things made of quadrilaterals.
• You can also encourage your 3^rd graders to use triangles and quadrilaterals to create beautiful patterns and designs, such as quilts, mosaics, origami, and art. They can use different colors, sizes, and orientations of these shapes to make interesting and unique combinations. Ask them: “What kind of patterns or designs can you make with triangles and quadrilaterals”?
• Another way to use triangles and quadrilaterals is to measure angles and distances. For example, your kids can use a right triangle (a triangle with one 90-degree angle) and a protractor tool to measure any angle.
• They can also use a formula called the Pythagorean theorem to find the length of any side of a right triangle if they know the lengths of the other two sides. They can use a quadrilateral called a rectangle (a quadrilateral with four right angles) and a tool called a ruler to measure the length and width of any object.
• They can also use the area formula to find the amount of space inside any rectangle if they know its length and width. Ask them: “How can you use these tools and formulas to measure things in your home or school?”