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Drawing Triangles using Geometrical Instruments - Part 2

Example:

Draw an isosceles triangle PQR in which PQ = PR, QR = 6 cm and ∠PQR = 50°.

Step 1: Draw a straight line QR 6 cm long.


Step 2: Using a protractor draw an angle of 50° from Point Q.


Step 3: Using a protractor draw an angle of 50° from Point R.

The angles opposite the equal sides in an isosceles triangle are equal.
Therefore, ∠PQR = ∠PRQ = 50°.

Step 4: Mark the point where the two lines meet as P.
           ΔPQR is the required isosceles triangle.


Example 3

Draw a right-angled triangle XYZ with ∠XYZ = 90°, YZ = 5 cm and XY = 4 cm.

Step 1: Draw a straight line YZ 5cm long.


Step 2: Using a protractor draw a right angle (an angle of 90°) from Point Y.


Step 3: Mark the point X so that XY = 4 cm.
           Join Point X to Point Z.
           Δ is the required right-angled triangle.


Example 4   click here to watch the lesson video

Draw a triangle DEF with ∠DEF = 130°, ∠DFE = 20° and EF = 6 cm.

Step 1: Draw a straight line EF 6 cm long.


Step 2: Using a protractor draw an angle of 130° from Point E.


Step 3: Using a protractor draw an angle of 20° from Point F.


Step 4: Mark the point where the two lines meet as Point D.
           ΔDEF is the required triangle.