All About Cylinders

A cylinder is a three-dimensional shape in geometry. A cylinder is round and has a top and bottom in the shape of a circle. The top and the bottom are flat and always the same size. I think the best way to describe the shape of a cylinder is to think of a can of soup!

Can of Soup

Volume of a Cylinder

The volume of a cylinder tells us how much space it has on the inside of it. If you had a can of pop, the volume would be equal to how much pop fills the entire can.

In the formula to find the volume of a cylinder, you will need to know the height and radius of the cylinder. The height is basically how tall it is. The radius is equal to half of the length of the diameter of its circular top or bottom. Remember also that the number pi can be rounded to 3.14.

Volume of a Cylinder

Surface Area of a Cylinder

The surface area of a cylinder tells us how much space covers the entire surface of the cylinder. If you were to wrap a can of Pringles with wrapping paper for a birthday gift, the amount of wrapping paper that is used would be equal to the surface area of the Pringles can. To find the surface area of a cylinder, you will need to know the height and radius of a cylinder.

Surface Area of Cylinder

Wrapping Food

Now image that you need to cover a cylindrical piece of cheese with foil. After measuring its dimensions, you figured out that the height is 3 inches and the radius is 1 inch. In order to figure out how much foil you need to cover the entire piece of cheese, you need to calculate the surface area!

Angles

When your child is learning about angles, it may be difficult for them to distinguish between different angle sizes. There are a variety of mathematical lessons associated with angles, and it is important for children to learn some simple patterns that can help them learn about the different types of angles.

Angles are measured in degrees, and there are three different types of angles: right, acute, and obtuse. Also, angles are measured by the space that exists in between its two connected lines, as shown in the images below. Right angles are the most basic point of reference for students when they learn about acute and obtuse angles, as they measure to be 90 degrees.

Acute angles are angles that measure between 0 and 90 degrees. These types of angles can be identified by their narrowness; the space in between the two lines of the angle is smaller in comparison to that of a right angle, as depicted by the image below. Compare this 54-degree angle to the 90-degree angle image. Notice how the 54-degree angle has a space that is smaller than the 90-degree angle.

Obtuse angles are angles that exclusively measure between 90 and 180 degrees. The reason why a measurement of 0 to 180 degrees is not applicable to obtuse angles is because angles that measure from 0 to 90 degrees are considered to be acute angles. These angles look wider and broader than acute angles, and any angle larger than a right angle is considered obtuse. Compare the 130-degree angle to the 90-degree angle, and then compare it to the 54-degree angle. You will notice that the 130-degree angle is much larger than both.

Make sure to use a right angle as a point of reference when trying to distinguish between different angle types. Any angle that is wider than 90 degrees, no matter how small the gap, is considered obtuse; any angle that is smaller than 90 degrees is considered acute. Use this easy tip to help your child along as they learn more about their angles.