Answer:

Step-by-step explanation:
We have,
Radius of the circle is 12 cm
Arc length, l = 21 cm
It is required to find the central angle of the circle. The formula for the length of an arc of a circle is :

is central angle

So, the angle at the centre of the circle is
.
Answer:
10,20,40
Step-by-step explanation:
They all have a factor of 2,10, and 1

An expression having five terms which is equivalent to above term is :
Hello!
10 seconds to return to the ground.
7 seconds to reach 576 feet above the ground.
Find the amount of time taken to reach the ground by setting the equation equal to 0:
0 = -16t² + 80t + 800
Factor out -16 from the equation:
0 = -16(t² - 5t - 50)
Factor the terms inside of the parenthesis:
0 = -16(t - 10)(t + 5)
Find the zeros:
t - 10 = 0
t = 10
t + 5 = 0
t = -5
Time can only be positive in this instance, so the correct answer is 10 sec.
Find the time by substituting in 576 for the height:
576 = -16t² + 80t + 800
Subtract 800 from both sides:
-224 = -16t² + 80t
Rearrange:
0 = -16t² + 80t + 224
Simplify:
0 = -16(t² - 5t - 14)
0 = -16(t - 7)(t + 2)
t = 7 seconds.
Answer:
BC = 30.73
Here,

so first solve for QD




Now! <u>using Pythagoras theorem,</u>
- BC = 30.73 ( rounded to nearest hundredth )