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
.
The required simplified value of B - A = -6.
<h3>What is simplification?</h3>
The process in mathematics to operate and interpret the function to make the function simple or more understandable is called simplifying and the process is called simplification.
Since, line Ax + By = 3 and x + 3y = -5 are parallel than slope of both the line will be same,
m = -1/3 = -A/B
From above
A = B/3 - - - - -(1)
Now line Ax + By = 3 passed through the point (-7, 2). So,
-7A + 2B = 3
from equation 1
-7B/3 + 2B = 3
-B/3 = 3
B = -9
Now put B in equation 1
A = -9 / 3
A = -3
Here,
B - A = -9 + 3 = -6
Thus, the required simplified value of B - A = -6.
Learn more about simplification here: brainly.com/question/12501526
#SPJ1

- Given - <u>A </u><u>trapezium</u><u> </u><u>ABCD </u><u>with </u><u>non </u><u>parallel </u><u>sides </u><u>of </u><u>measure </u><u>1</u><u>5</u><u> </u><u>cm </u><u>each </u><u>!</u><u> </u><u>along </u><u>,</u><u> </u><u>the </u><u>parallel </u><u>sides </u><u>are </u><u>of </u><u>measure </u><u>1</u><u>3</u><u> </u><u>cm </u><u>and </u><u>2</u><u>5</u><u> </u><u>cm</u>
- To find - <u>Area </u><u>of </u><u>trapezium</u>
Refer the figure attached ~
In the given figure ,
AB = 25 cm
BC = AD = 15 cm
CD = 13 cm
<u>Construction</u><u> </u><u>-</u>

Now , we can clearly see that AECD is a parallelogram !
AE = CD = 13 cm
Now ,

Now , In ∆ BCE ,

Now , by Heron's formula

Also ,

<u>Since </u><u>we've </u><u>obtained </u><u>the </u><u>height </u><u>now </u><u>,</u><u> </u><u>we </u><u>can </u><u>easily </u><u>find </u><u>out </u><u>the </u><u>area </u><u>of </u><u>trapezium </u><u>!</u>

hope helpful :D
Answer:
there is no value its letter
Step-by-step explanation:
there is no value to a letter duh