Question

Construct an isosceles triangle whose equal sides are 7 cm each and the base side is 5 cm. Draw all its lines of symmetry. 

Answer 1

Steps of construction: 

(i) Draw a line segment AB = 5 cm 

 

(ii) With A as centre, cut an arc of 7 cm on one side of line segment AB. 

 

(iii) With B as centre, cut an arc of 7 cm on same side of line segment AB. Let the point be C. 

 

(iv) Join AC and BC. ABC is the required triangle. 

 

(v) Draw angle bisector of angle C meeting AB at D. 

 

(vi) CD is perpendicular bisector of AB and AC=BC. Hence CD is the line of symmetry. 

 

Isosceles triangle has only one line of symmetry.