Introduction to Geometry and Angles
Geometry is the branch of mathematics that studies about various shapes and sizes. It is concerned with properties of various shapes like length, areas and volumes.
Angle is a meeting point of two rays. If two rays have a common end point we say an angle is formed. The rays are called the arms of the angle and the common meeting point is the vertex of the angle. Most commonly used unit to measure an angle is the degrees denoted as o). One full circle has 360 o. Smaller units to degrees is the minutes and seconds. 1o has 60 minutes and one minute has 60 seconds. This minutes and seconds should not be confused with the units for time.There are also other units like radians, steradians etc. In this discussion we will use only degrees. I like to share this What are Adjacent Angles with you all through my article.
In this discussion we will briefly see the instruments used for measuring an angles.There are five instruments used for measuring the angle as below and the most commonly used is the protractor. A protractor is semi circular in shape and is marked from 0 o to 180 o.
It is very easy to use a protractor. Place the protractor with the base line of the protractor over one of the rays or arms of the angle and the centre point of the base line at the vertex of the angle. The other arm of the angle will coincide with one of the lines in the protractor and you can read the angle marked in the protractor.
Protractors can also be used measure three dimensional angles. Lets us take a brief look at the other instruments used to measure angles
Instruments to Measure Angles
The main instruments to measure angle are discussed below
Inclinometer : An inclinometer is used to measure angles of inclination with respect to the vertical. It is also known as a level gauge. Inclinometer is widely used in surveying, geophysics, automotive safety systems, aircrafts etc to measure inclinations.
Gonimeter :A gonimeter helps to rotate an object to a particular angle. The word gonimeter in Greek means angle measure
Compass :Compass uses the Earth’s magnetic field and is widely used in navigation. A compass is any device that can sense the Earth’s magnetic field and indicate direction , A magnetic compass is a very old instruments and it traces its origin somewhere around 247 BC. But still it finds application in modern navigational systems like GPS (Global positioning System)
Sextant :A sextant can measure angle between two objects and is primarily used in determining angles of celestial objects
Theodolite : A theodolite is used in surveying to find the angles of planes. There are modern theodolites fitted with telescopes and can measure angles precisely.
Understanding online college math help is always challenging for me but thanks to all math help websites to help me out.
Some Practical Exercises on Measuring Angles
Prob 1: Can you think of a situation where you need to measure an angle in day to day life?
Hint: Think of carpentry, plumbing, masonry work etc
Prob 2: Can you think of activities or instruments where we make use of our intuitive power on judging angles?
Hint: some examples are we read time in a dial clock just by glance as we can guess the angle between the needles and judge the time, a drive turns the steering at an angle depending on the angle by which vehicle needs to be turned. Think of other examples on these lines
Prob 3: Make a cut out of a protractor on a cardboard and try making graduations at angle of 30o, 45o, 60o, 75o, 90o, 105o, 120o, 135o, 150o and 180o
Geometry is the branch of mathematics that studies about various shapes and sizes. It is concerned with properties of various shapes like length, areas and volumes.
Angle is a meeting point of two rays. If two rays have a common end point we say an angle is formed. The rays are called the arms of the angle and the common meeting point is the vertex of the angle. Most commonly used unit to measure an angle is the degrees denoted as o). One full circle has 360 o. Smaller units to degrees is the minutes and seconds. 1o has 60 minutes and one minute has 60 seconds. This minutes and seconds should not be confused with the units for time.There are also other units like radians, steradians etc. In this discussion we will use only degrees. I like to share this What are Adjacent Angles with you all through my article.
In this discussion we will briefly see the instruments used for measuring an angles.There are five instruments used for measuring the angle as below and the most commonly used is the protractor. A protractor is semi circular in shape and is marked from 0 o to 180 o.
It is very easy to use a protractor. Place the protractor with the base line of the protractor over one of the rays or arms of the angle and the centre point of the base line at the vertex of the angle. The other arm of the angle will coincide with one of the lines in the protractor and you can read the angle marked in the protractor.
Protractors can also be used measure three dimensional angles. Lets us take a brief look at the other instruments used to measure angles
Instruments to Measure Angles
The main instruments to measure angle are discussed below
Inclinometer : An inclinometer is used to measure angles of inclination with respect to the vertical. It is also known as a level gauge. Inclinometer is widely used in surveying, geophysics, automotive safety systems, aircrafts etc to measure inclinations.
Gonimeter :A gonimeter helps to rotate an object to a particular angle. The word gonimeter in Greek means angle measure
Compass :Compass uses the Earth’s magnetic field and is widely used in navigation. A compass is any device that can sense the Earth’s magnetic field and indicate direction , A magnetic compass is a very old instruments and it traces its origin somewhere around 247 BC. But still it finds application in modern navigational systems like GPS (Global positioning System)
Sextant :A sextant can measure angle between two objects and is primarily used in determining angles of celestial objects
Theodolite : A theodolite is used in surveying to find the angles of planes. There are modern theodolites fitted with telescopes and can measure angles precisely.
Understanding online college math help is always challenging for me but thanks to all math help websites to help me out.
Some Practical Exercises on Measuring Angles
Prob 1: Can you think of a situation where you need to measure an angle in day to day life?
Hint: Think of carpentry, plumbing, masonry work etc
Prob 2: Can you think of activities or instruments where we make use of our intuitive power on judging angles?
Hint: some examples are we read time in a dial clock just by glance as we can guess the angle between the needles and judge the time, a drive turns the steering at an angle depending on the angle by which vehicle needs to be turned. Think of other examples on these lines
Prob 3: Make a cut out of a protractor on a cardboard and try making graduations at angle of 30o, 45o, 60o, 75o, 90o, 105o, 120o, 135o, 150o and 180o