Draw a line ‘ l ’ and mark a point ‘P’ on it

Measure 5.5 cm using compass placing the pointer at ‘0’ and the pencil pointer at 5.5 cm.

Place the pointer of the compass at ‘ P ’ then draw a small arc on the line ‘l ’ with the pencil pointer. It cuts the line ‘ l ’ at a point and name that point as ‘Q’

Now, PQ is the required line segment of length 5.5 cm.

(i) and (iv) are complementary angles
(ii) and (iii) are non-complementary angles

Paralell line:
\( \overline{\mathrm{AB}} \ \text{and}\)  \( \overline{\mathrm{DC}},\)
\( \overline{\mathrm{AD}} \ \text{and}\) \(\overline{\mathrm{BC}},\)
\(\overline{\mathrm{DC}} \text { and } \overline{\mathrm{HG}}, \)
\(\overline{\mathrm{AD}} \text { and } \overline{\mathrm{EH}},\)
\( \overline{\mathrm{AE}} \text { and } \overline{\mathrm{DH}}, \)
\( \overline{\mathrm{DH}} \text { and } \overline{\mathrm{GG}}\)
Intersecting lines:
\(i) \ \overline{\mathrm{AB}}, \overline{\mathrm{AE}}, \overline{\mathrm{AD}}\\ ii) \ \overline{\mathrm{DA}}, \overline{\mathrm{DH}}, \overline{\mathrm{DC}}\\ iii) \ \overline{\mathrm{CB}}, \overline{\mathrm{CG}}, \overline{\mathrm{CD}}\\ iv)\ \overline{\mathrm{HD}}, \overline{\mathrm{HG}}, \overline{\mathrm{HE}}\\ v) \ \overline{\mathrm{EA}}, \overline{\mathrm{EH}}_{, . .}\)

i), iii) are obtuse angles

(1) An Acute angle:

(2) An Obtuse Angle: 
 
(3) A right Angle: 

(4) A straight Angle: