**Basic Geometrical Ideas**

**Question 1.Draw a rough sketch of a triangle ABC. Mark a point P in its interior and a point Q in its exterior. Is the point A in its exterior or in its interior?**

**Solution:**

Rough sketch of a ∠ABC as shown.

Points P and Q are marked in the interior and exterior of ∆ABC.

Point A lies on the ∆ABC.

**Question 2.****(a)** Identify three triangles in the figure.**(b)** Write the names of seven angles.**(c)** Write the names of six line segments.**(d)** Which two triangles have ZB as common?**Solution:(a)** Three triangles are identified in the figure as ∆ ABC, ∆ ABD and ∆ ACD.

**(b)**The names of seven angles are ∠BAD, ∠BAC, ∠CAD, ∠ABD, ∠ACD, ∠ADC and ∠ADB.

**(c)**The names of six line segments are AB, BD, DC, CA, BC and AD.

**(d)**∆ ABC and ∆ ABD have ∠B as common.