Free Lines and Angles 03 Practice Test - 7th grade 

A clock has a total of 360°.
The angle between any two consecutive numbers on a clock  
= $\frac{{360}^{\circ }}{12}$ = 30${}^{\circ }$​ [$\because$ a clock has 12 divisions]

At 8 o'clock, the minute hand is at 12 and the hour hand is at 8 and there are 4 divisions between 8 and 12. 

$\therefore$ The angle between them  = 4 × 30${}^{\circ }$
                                               = 120${}^{\circ }$

Hence the angle formed at 8 o'clock is an obtuse angle since it is more than 90° and less than 180°.

From the figure given in the question, we can observe that

$\angle$3 = 75${}^{\circ }$
(Vertically opposite angles)

$\angle$2 +75${}^{\circ }$ = 180${}^{\circ }$
(Angles on a straight line)

$\Rightarrow$ $\angle$2 = 180${}^{\circ }$- 75${}^{\circ }$ = 105${}^{\circ }$

$\angle$2 = $\angle$4
(Vertically opposite angles)

$\Rightarrow$$\angle 4$ = 105°

Exterior angles lie outside the parallel lines. The exterior angles are 1, 2, 7, 8.

$\angle$1 and 72${}^{\circ }$ form a linear pair.
So, $\angle$1 + 72${}^{\circ }$ = 180°
$\Rightarrow$  $\angle$1 =  180°- 72${}^{\circ }$ 
$\Rightarrow$   $\angle$1 = 108°
Similarly, $\angle$2 and 98${}^{\circ }$ form a linear pair.
So, $\angle$2 + 98${}^{\circ }$ = 180°
$\Rightarrow$  $\angle$2 =  180°- 98${}^{\circ }$ 
$\Rightarrow$   $\angle$2 = 82°
$\therefore \angle 1+\angle 2=108°+82°=190°$

A circular clock consists of 360 degrees.  The angle between any two consecutive numbers of a clock is.

$\frac{360}{12}$ = 30${}^{\circ }$​.

At 2 PM, the minute hand is at 12 and the hour hand is at 2.

Therefore the angle between them  = 2 × 30 = 60${}^{\circ }$​

Two angles are called supplementary angles if their sum is 180${}^{\circ }$.

So, 30${}^{\circ }$ + 2x = 180${}^{\circ }$

Hence, x = 75${}^{\circ }$.

If three lines are cut by two transversals, then there are 6 points of intersection.

Angles less than 90${}^{\circ }$ are acute angles.

An obtuse angle is more than 90° but less than 180°

Angles equal to 90${}^{\circ }$ are right angles.

Infinite number of transversals can be drawn for any two given lines.

Parallel lines never intersect.