Answer:
Two triangles are congruent if their corresponding sides are equal in length and their corresponding interior angles are equal in measure. We use the symbol ≅ to show congruence. Corresponding sides and angles mean that the side on one triangle and the side on the other triangle, in the same position, match.Step-by-step explanation:
We cannot calculate the confidence interval without the sample size. However, for the second question, the sample size needed would be 49.
The formula we use is

To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value is closest to a z-score of 2.33.
Using the z-score, our standard deviation (9) and our margin of error (3), we have:
When you've got a squares bracket, this simply becomes the bracket twice, therefore, (r+s)2 becomes (r+s)(r+s)
You've then go to use FOIL, and this gives you r^2+rs+sr+s^2, and this cannot be simplified any further.
Therefore, the product of this is r^2 + s^2 + rs + sr
Hope this is what you're looking for :)
Answer: 42.21 km
Step-by-step explanation:
We can solve this using trigonometry, since we have the following data:
is the the angle of elevation
is the horizontal distance between the plane and the radar station
is the hypotenuse of the right triangle formed between the radar station and the airplane
Now, the trigonometric function that will be used is <u>cosine</u>:
because
is the adjacent side of the right triangle
Finding
:
Here, exterior angles are 1, 2, 7 & 8 as they are outside the parallel lines, & among them, alternates are: 1 with 7 and 2 & 8. 1 & 7 is not in option but 2 and 8 is there in C
In short, Your Answer would be Option C
Hope this helps!