An angle is the opening formed by two rays (called sides) that start from the same point, called the vertex. It is measured in degrees (°) with a protractor, and that measure tells you how far you have to turn from one side to the other. A full turn is 360°.
Types of angles and an example
According to their measure, angles are classified as:
Acute: less than 90° (for example, 45°).
Right: exactly 90°, like the corner of a sheet of paper or a notebook.
Obtuse: between 90° and 180°.
Straight: exactly 180°, that is, a straight line.
Think of a clock: at 3:00 the hands form a right angle of 90°; at 6:00 they form a straight angle of 180°. Every hour, the hour hand moves 30°.
Why does it matter for kids?
Angles are studied from primary school and are the foundation of geometry, but they also appear in real life: in architecture, sports, video games and coding. When a child moves a character in Scratch or draws a shape with code, they use angles to set the turns. Measuring and classifying angles trains precision and logical thinking. At Algonova kids apply angles by coding their own games, and they also learn to calculate the perimeter and area of the shapes they create.
Frequently asked questions about angles
What is an angle?
An angle is the opening formed by two rays, called sides, that start from the same point, called the vertex. It is measured in degrees (°) with a protractor, and that measure tells you how far you have to turn from one side to the other. A full turn is 360°. The corner of a sheet of paper or a notebook is the easiest angle to recognize: it is exactly 90° and it is called a right angle. A clock is another good example: at 3:00 the hands form a right angle of 90°, and at 6:00 they form a straight angle of 180°; every hour, the hour hand moves 30°. Angles are studied from primary school and are the foundation of geometry.
What are the types of angles?
By their measure, angles fall into four main types: acute, less than 90° (for example, 45°); right, exactly 90°, like the corner of a sheet of paper or a notebook; obtuse, between 90° and 180°; and straight, exactly 180°, that is, a straight line. Beyond those there are the reflex angle and the full angle, which measures 360° and equals one complete turn. A quick way to sort them is to compare with the corner of a sheet: if the opening looks tighter than that corner, the angle is acute; if it looks wider, it is obtuse. On a clock, 3:00 gives a right angle and 6:00 gives a straight angle. Angles are studied from primary school onward.
How do you measure an angle?
An angle is measured with a protractor, which gives the measure in degrees (°). First find the vertex, the point where the two sides meet. Place the center point of the protractor right on that vertex. Turn the protractor until one of the sides lies on the 0° mark. Then follow the other side and read the number it crosses: that number is the measure of the angle. A tip for your child: if the opening looks tighter than the corner of a sheet of paper, the answer should be less than 90°; if it looks wider, more than 90°. That way a misread number gets caught early. The measure tells how far you turn from one side to the other, and a full turn is 360°.
How many degrees is a right angle?
A right angle is exactly 90°. It is the angle formed by the corner of a sheet of paper, a table or a notebook, which makes it the easiest one to recognize at a glance. It works as the reference for sorting the rest: an angle under 90° is acute, and one between 90° and 180° is obtuse. Four right angles in a row complete a full turn of 360°, and two of them make a straight angle of 180°, that is, a straight line. A clock shows it clearly: at 3:00 the hands form a right angle of 90°. When your child codes a turn in Scratch, a 90° turn is exactly this angle. Right angles are the foundation of the geometry taught from primary school.
