Drawing triangles using ruler and protractor

(i) Draw a line AB.
(ii) Draw an angle of 90 degrees at A using a
protractor and a ruler.
(iii) Mark a point C on the line making an
angle of 90 degrees with AB.
(iv) Draw CB.

Equilateral triangle

Procedure
(i) Draw a line AB.
(ii) Draw an angle of 60 degrees at A and at B.
(iii) Extend the lines making the angles at A and B so that they meet at C.

ABC in the figure above is an equilateral triangle.