To form a linear pair means that when added, they equal 180 degrees.
but if they have equal measures....180/2 = 90...then they would both equal 90 degrees.....and 90 degrees is a right angle.
So ABC and CBD are both right angles
Answer:
The rate of change in surface area when r = 20 cm is 20,106.19 cm²/min.
Step-by-step explanation:
The area of a sphere is given by the following formula:

In which A is the area, measured in cm², and r is the radius, measured in cm.
Assume that the radius r of a sphere is expanding at a rate of 40 cm/min.
This means that 
Determine the rate of change in surface area when r = 20 cm.
This is
when
. So

Applying implicit differentiation.
We have two variables, A and r, so:



The rate of change in surface area when r = 20 cm is 20,106.19 cm²/min.
I think it’s direct variation y= 12/x i’m note 100% sure tho
Answer:

Step-by-step explanation:
There are eight 2's so that equals 
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