Geometry is a branch of maths that deals with angles, lines, segments, points, etc and helps us to determine the spatial relationship between them. It is one of the oldest parts of mathematics. As we know there are different kinds or types of geometry that can be focused on. Some of them are mentioned below in points:
- Differential geometry
- Algebraic geometry
- Topology
- Discrete geometry
- Spherical geometry
- Hyperbolic geometry
- Euclidean geometry
Plane shape
As we know a plane is a two-dimensional shape or object which has no thickness. They can be extended into infinity. The lines of the plane objects or figures can be straight, curved, or both of them in combination. Some of the examples of plane shapes are rectangle, square, rhombus, etc. There are five basic plane shapes mentioned below:
- Rectangle
- Circle
- Triangle
- Rhombus
- Square
- Trapezoid
What is a circle?
The circle is a plane figure connected with different points having no edges or corners. They are round in shape. Coin, dinner plate, wheels, etc are some of the real-life examples of circles. Circles are considered a plane shape because it has no thickness and can be extended to infinity.
Properties of Circle
- The diameter of the circle is the longest chord.
- The radius which is perpendicular to the chord bisects the chords.
- The radius and circumference of the circle are always proportional.
- A perpendicular line from the centre of the circle bisects the chords.
- An inscribed angle subtended by a diameter is a right angle.
Is a circle a straight line?
Answer:
The line which is placed at 180 degrees is a straight line. And, when we see a circle, it has uncountable or infinite numbers of sides and internal angles measured as 180 degrees. The interior angle of a circle is also 180 degrees which means equal to a straight line.
Hence, a circle is a straight line.
Sample Questions
Question 1. Which is the longest chord of the circle?
Answer:
The diameter is the longest chord of the circle.
Question 2. What can be considered as the right angle in a circle?
Answer:
An inscribed angle subtended by a diameter can be considered as a right angle.
Question 3. Which line in a circle bisects the chords?
Answer:
A perpendicular line in a circle bisects the chords.
Question 4. How many edges does a circle have?
Answer:
A circle has no edges because an edge of a closed figure has to be a straight line.
Question 5. Why are circles considered to be infinite?
Answer:
Circles are considered to be infinite because they are polygons with an infinite number of sides.