Measurements and Geometry

Transcript

Measurements and Errors We learnt that By vertically opposite angles ∠ 1 = ∠ 3 ∠ 2 = ∠ 4 Let’s measure the angles using a protractor and check Sometimes numbers are not equal or linear pair is not 180° The reason could be Measurement errors because of improper use of measuring instruments — in this case, a protractor Variation in the thickness of the lines drawn. The “ideal” line in geometry does not have any thickness! But it is not possible for us to draw lines without any thickness In geometry, we create ideal versions of “lines” and other shapes we see around us, and analyse the relationships between them. For example, we know that the angle formed by a straight line is 180°. So, if another line divides this angle into two parts, both parts should add up to 180°. We arrive at this simply through reasoning and not by measurement. When we measure, it might not be exactly so, for the reasons mentioned above. Still the measurements come out very close to what we predict, because of which geometry finds widespread application in different disciplines such as physics, art, engineering and architecture.