Answer:
90°, 270°
Step-by-step explanation:
2r sin(Ф/2) = c
2r sin (Ф/2) = √2r
divide both sides by 2r
sin (Ф/2) = √2r/2r
sin(Ф/2) = √2/2
From the unit circle sin is √2/2 at 45°, and 135°
so Ф/2 = 45
Ф=90°
and Ф/2 = 135
Ф= 270°
Wilda can do the job in 4 hours ... she does 1/4 (or 0.25) of it each hour.
Karla can do it in 5 hours ... she does 1/5 (or 0.2) of it each hour.
Wilda worked alone for 1 hour ... 0.25 of the job was done before her helper
arrived. So only 0.75 of the job remained to be done together.
Working together, they accomplish (0.25 + 0.2) = 0.45 of the job in 1 hour.
How many times do they need to do 0.45 of the job in order to finish
the 0.75 of it that remains ? That's the number of hours it will take them,
working together.
0.75 / 0.45 = <em>1 and 2/3</em>
After Wilda worked alone for 1 hour and Karla came along to join her, it will
take them another <em>1 hour and 40 minutes</em> to finish the job and go for a swim.
like i said the ? would be a 5
Answer:
$1.5
Step-by-step explanation:
$7- 5.50= 1.5
