So 1 hour is 360÷ 12=30 degrees.

10 is 1/6 hours.

So it's 30÷6=5 degrees.

So the hour hand is 9×30+5=275 degrees at 10 from 0 to 9: 00.

So it is 360-275=85 degrees from 12.

The minute hand is a lap of 60 minutes.

So 10 is 360÷6=60 degrees.

So the included angle is 85+60= 145 degrees.