Geometry is a method that deals with lines, angles, shapes of items, sizes, length and breadths. To showcase shapes on paper these are drawn properly with the help of instruments such as scales, protectors or compasses. The easiest construction is that of a line first a point is started and increased slowly to construct a line. A line may have a specified quantity or an immeasurable length. Correspondingly, angles, circles and other shapes can be drawn by using proper methods and the provided lengths and breadths. Geometrical construction refers to the construction of lines, line segments, shapes, circles and other units with the help of scale, compass and protractor . Majority of the geometrical figures focus on the constructions of line segments, the construction of collateral and vertical lines, equidistant lines, circles and even construction of tangents to the circles. The following section summarises the basic geometrical drawings for angles and circles.
Angles
There are three types of angles. The following lines summarise how these types of angles can be created by using a scale or a protractor.
Acute Angle: An angle whose measure is below 90 degrees is called an acute angle. An acute angle is drawn by the following formula
1) A straight line is drawn by using a scale and the terminal points are named as P and Q.
2) A protractor is placed on the point P such that the point corresponds with the middle of the protractor.
3) The lower end of the scale of the protractor is thought, 70 degrees angle is recognised and labelled it as R . Point P and R are joined to create an acute angle RPQ which is equal to 70 degrees.
Obtuse Angle: An angle whose measure is more than 90 degrees is called an obtuse angle. An obtuse angle is drawn by using the following formula
1) A straight line is constructed by using a scale and the terminal points are marked as X and Y.
2) The protractor is situated on point X such that the point corresponds with the middle of the protractor.
3) The lower end of the scale of the protractor is thought, 130 degrees angle is recognised and named as Z. X and Z are connected creating an obtuse angle ZXY.
Right Angle: A angle whose measure is equal to 90 degrees is called as a right angle. A right angle is drawn by using the following formula:
1) A straight line is constructed by using a scale and the terminal points are named as R and S.
2) The protractor is situated on the point R such that the point corresponds with the middle of the protractor.
3) The lower end of the scale of the protractor is thought, 90 degrees angle is recognised and T point is identified. T and R are joined by creating a right angle TSR= 90 degrees.
Circles
Some necessary terms related to circles are highlighted below:
a) Circumference: Circumference is defined as the perimeter of the circle.
b) Radius: Radius is measured as the length between the middle of the circle to any point of the perimeter of the circle.
c) Diameter: Diameter is a line segment moving through the middle of the circle whose terminal points connect with the perimeter of the circle.
d) Chord: A chord is a line segment connecting any two points on the perimeter of a circle.
The following steps for construction of a circle are as follows:
1) A scale is used for drawing a line segment 6 cm, and then line segments is measured by a compass.
2) After that a circle is drawn by the help of a compass and a radius is constructed by joining the middle point of the circle to the end point.
