[tex]\large\underline{\sf{Solution-}}[/tex]
We know,
- Angle traced by minute hand in 60 minutes is 360°.
So,
- Angle traced by minute hand in 1 minutes is 6°.
So,
- Angle traced by minute hand in 20 minutes is 120°.
Now,
- Angle traced by hour hand in 12 hours is 360°.
So,
- Angle traced by hour hand in 1 hour is 30°.
Now,
7 hour 20 minutes = [tex] \rm \: 7\dfrac{20}{60} [/tex]=[tex] \rm \: 7\dfrac{1}{3} [/tex]=[tex] \rm \: \dfrac{22}{3} \: hours[/tex]
So,
- Angle traced by hour hand in [tex] \rm \: \dfrac{22}{3} [/tex] hours is [tex] \rm \: \dfrac{22}{3}×30 [/tex]= 220°
So,
Angle between the minute hand and hour hand when time is 7.20 am = 220° - 120° = 100°.
[tex]\rule{190pt}{2pt}[/tex]
Additional Information :-
[tex]\begin{gathered}\: \: \: \: \: \: \begin{gathered}\begin{gathered} \footnotesize{\boxed{ \begin{array}{cc} \small\underline{\frak{\pmb{ \red{More \: Formulae}}}} \\ \\ \bigstar \: \bf{sin(x - y) = sinx \: cosy \: - \: siny \: cosx}\\ \\ \bigstar \: \bf{sin(x + y) = sinx \: cosy \: + \: siny \: cosx}\\ \\ \bigstar \: \bf{cos(x + y) = cosx \: cosy \: - \: sinx \: siny}\\ \\ \bigstar \: \bf{cos(x - y) = cosx \: cosy \:+\: siny \: sinx}\\ \\ \bigstar \: \bf{tan(x + y) = \dfrac{tanx + tany}{1 - tanx \: tany} }\\ \\ \bigstar \: \bf{tan(x - y) = \dfrac{tanx - tany}{1 + tanx \: tany} }\\ \\ \end{array} }}\end{gathered}\end{gathered}\end{gathered}[/tex]