All sides are the same length (congruent) and all interior angles are the same size (congruent). To find the measure<span> of the angles, we know that the </span>sum<span> of all the angles is 1080 degrees (from above)... And there are eight angles... So, the </span>measure<span> of the interior angle of a regular </span>octagon<span> is 135 degrees</span>
Answer:
a) The half life of the substance is 22.76 years.
b) 5.34 years for the sample to decay to 85% of its original amount
Step-by-step explanation:
The amount of the radioactive substance after t years is modeled by the following equation:
In which P(0) is the initial amount and r is the decay rate.
A sample of a radioactive substance decayed to 97% of its original amount after a year.
This means that:
Then
So
(a) What is the half-life of the substance?
This is t for which P(t) = 0.5P(0). So
The half life of the substance is 22.76 years.
(b) How long would it take the sample to decay to 85% of its original amount?
This is t for which P(t) = 0.85P(0). So
5.34 years for the sample to decay to 85% of its original amount
Answer:
To find the slope, you divide the difference of the y-coordinates of 2 points on a line by the difference of the x-coordinates of those same 2 points .
Step-by-step explanation:
There's an infinite number of equivalent ratios for 27:15, these are the ones that just came to my mind:
27:15 = 54:30 (because 27 * 2 = 54 and 15 * 2 = 30)
27:15 = 9:5 (because 27 / 3 = 9 and 15 / 3 = 5)
27:15 = 135:75 (because 27 * 5 = 135 and 15 * 5 = 75)