The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
Introduction
Practical geometry is a part of geometry that deals with the study of shapes, size, dimensions, and positions of different objects. Geometry helps us to draw and define different figures and shapes.
Steps:
Draw a line P and mark a point A outside of the line.
Take any other point, say Q, and join the lines PQ.
Now take B as a centre and take a radius of 4 cm.
Cut an arc on line P at C and AB.
Mark the intersection point as D on AB.
With A as a centre now and the same radius as before, cut an arc EF to cut AB at G.
Measure the arc length CD by placing a pointed tip of the compass at C and pencil tip opening at D.
With this opening, keep G as a centre and draw an arc to cut arc EF at H.
Join AH to draw a line Q.
∠ABC and ∠BAH are alternate interior angles. Therefore, P || Q.
Triangles can be constructed and classified based on two major concepts:
Sides:
Equilateral triangle: All three sides are equal.
Isosceles triangle: Two sides are equal.
Scalene triangle: All three sides are equal.
Angles:
Acute triangle: All angles measure less than 90 degree.
Obtuse triangle: One angle is greater than 90 degree.
cRight triangle: One angle is equal to 90 degree.
Construct a triangle DEF, given that DE = 7.6 cm, EF = 4.5 cm, and DF = 8.6 cm.
Steps:
Draw a line segment EF of length 4.5 cm.
Draw an arc of a radius 7.6 cm with E.
Draw an arc of radius 8.6 cm with F.
Mark the intersection of both the arcs with point D.
Join the line segment DE and DF.
You will get a triangle DEF.
Construct ΔLMN with LM = 6.4 cm, LM = 5.5 cm, and ∠M = 45 degree.
Steps:
Draw a line segment LM of length 6.4 cm.
At point M, draw a line segment MX with an angle of 45 degree with LM.
Take point M as the centre, measure an arc of 5.5 cm.
Draw an arc of 5.5 cm that cuts MX at point Y.
Join MN.
ΔLMN is ready.
Construct ΔPQR with ∠P = 40o, ∠Q = 100 degree, and XY = 7.2 cm.
Steps:
Draw a line segment PQ of length 7.2 cm.
At point P, draw a ray named PA marking an angle of 40 degree with PQ.
At point Q, draw an angle of 100 degree with PQ.
Draw the line segment QR.
Extend the ray PA to intersect QR at point B.
The point at which both the lines PA and QR intersect is point B.
ΔABC is now complete.
Construct ΔABC, with ∠B = 90 degree, BC = 6 cm, and AC = 10 cm.
Steps:
Draw a line segment BC of length 6 cm.
At point B, draw BX ⊥ BC, which is perpendicular to each other.
To cut BX at point A with C as the centre, draw an arc of radius 10 cm.
Join AC.
ΔABC is complete.
What is practical geometry?
Practical geometry is a part of geometry that deals with the study of shapes, size, dimensions, and positions of different objects.
What is geometry in simple words?
Geometry is the branch of mathematics related to the study of sizes, shapes, and distances of different figures and objects. Shapes of 2D and 3D are also studied in geometry.
What is the use of geometry?
Geometry is used in mapping, architecture, interior design, medical operations, and surgeries, etc.
What are the three types of geometry?
The three types of geometry are Euclidean, Spherical, and Hyperbolic.
How do you do practical geometry?
Practical geometry is practised by constructing different shapes, figures, and measurements.