Answer:
The time now is 7 pm
Step-by-step explanation:
Suppose that now is the time T.
We know that:
"if time is four hours from now, the time left till midnight would be a quarter that if it is one hour from now".
Then:
if we define midnight as 12, and we assume that T is in the pm range.
Then the "time left till midnigth, assuming that the time is four hours from now" will be written as (12 - (T + 4))
With this in mind, we can write the problem as:
12 - (T + 4) = (1/4)*( 12 - (T + 1))
Now we can solve this for T.
12 - T - 4 = (1/4)*(12 - T - 1)
8 - T = (1/4)*(11 - T)
4*(8 - T) = 11 - T
32 - 4*T = 11 - T
32 - 11 = -T + 4*T
21 = 3*T
21/3 = T
7 = T
Then T = 7 pm
The time now is 7 pm
So a pentagon is constructed by five identical triangles, that's why you can find the area of one triangle and multiply it with 5:
A_pentagon=A_triangle*5
To find the area of a triangle you must use tangens.
You can watch this for more on that on youtube.
For the length of an arc or a portion of a circle you can find it using:
arc lenght = 2π*r(A/360), where A=angle.
So if you know radians, then 2π is a whole circle. And to calculate for the specific circle you have to use the radius. That's why you multiply with radius, which is the only difference between any two different circles. you then multiply with the part of the circle that you want to find the lenght for, which is A/360 (because there are 360° in a circle)
I hope that helped.
Answer:
x=−6
x=2
Step-by-step explanation:
Combine like terms and use the properties of equality to get the variable on one side of the equal sign and the numbers on the other side. Remember to follow the order of operations.
∣x+2∣−5=−1
Add 5 to both sides of the equation.
∣x+2∣=4
Use the definition of absolute value.
x+2=4
x+2=−4
Subtract 2 from both sides of the equation.
x=2
x=−6
OK. I used my calculator to evaluate sec(85 degrees).
My calculator doesn't have a "sec" button on it.
But I remembered that
sec of an angle = 1 / (cosine of the same angle) .
So I used my calculator to find cos(85), and then I hit the
" 1/x " key, and got 11.474, which I knew to be sec(85).
Answer:
c
Step-by-step explanation:
