1st day: 1 1/2 hours
2nd day: half of first day = 1/2 * 1 1/2 hours
3rd day: 2 1/2 times as long as first day: 2 1/2 * 1 1/2 hours
1 1/2 + 1/2 * 1 1/2 + 2 1/2 * 1 1/2 =
= 3/2 + 1/2 * 3/2 + 5/2 * 3/2
= 3/2 + 3/4 + 15/4
= 6/4 + 3/4 + 15/4
= 24/4
= 6
Answer: She studied for 6 hours over the 3-day period.
I'm not gonna give the answer because you have to solve it. Sorry. But I'll help you get it.
Step 1: solve the equation for each angle
Step 2: Add the totals from each angle
Step 3: Divide the total by 360
Step 4: You got your answer
I hope this helped! I'm sorry I answered really late.
That is true, perpendicular lines must form right angles

+

First, simplify the brackets. / Your problem should look like:

-
Second, simplify. / Your problem should look like:

Answer as fraction:

Answer as decimal: 0.8462