If Josie bought a mirror with 5 sides it would be a pentagon
Answer:
pi x diameter
Step-by-step explanation:
To calculate the circumference of a circle, simply multiply pi (3.14) by the diameter (straight line passing from side to side through the center of the circle)
For instance, if you knew the diameter of a circle was 6 inches. Simply multiply 6 inches by pi!
6 x pi = ?
? approximately equals 18.85 inches.
The circumference of the circle would be 18.85 inches!
If you only have the radius of the circle, simply multiply it by two to get your diameter. Remember, the radius is just half the length of the diameter.
Hope this helps! :)
Answer:
y = -3 when x = 4
Step-by-step explanation:
2x-4y = 20
x = 4
2(4) - 4y = 20
8 - 4y = 20
-4y = 12
y = -3
Step-by-step explanation:
are you sure you wrote the problem here correctly ?
because the distance will be 40km after less than half an hour just by the first car driving. way before the second car even starts.
to be precise, it would be after 60 minutes × 40 / 90
(= how many minutes of an hour are needed to reach 40km while going 90km/h) :
60 × 40 / 90 = 60 × 4 / 9 = 20 × 4 / 3 = 80/3 = 26.67 minutes.
but maybe the question was about 400km distance between the two cars.
so, the first car goes 90km/h for 2 hours.
at that moment it will be 2×90=180km ahead.
that would mean that 220km are still missing for the 400km assumption.
with each hour driving the first car makes 20km more than the second car.
to build up 220km that way would require
220/20 = 11 hours.
plus the 2 original head start hours this would make 13 hours as overall answer.
