Answer:
101
Step-by-step explanation:
According to the Law of Cosines, for any △ABC with side lengths a, b, and c, a2=b2+c2−2bccosA; b2=a2+c2−2accosB; and c2=a2+b2−2abcosC
.
The Law of Cosines can be used because all three side lentghs are known.
Set up the equation for the Law of Cosines:
a2=b2+c2−2bccosA
Substitute the known values into the Law of Cosines:
312=222+182−2(22)(18)cosA
Square the values and multiply:
961=484+324−792cosA
Add:
961=808−792cosA
Subtract 808
from both sides:
153=−792cosA
Divide both sides by −792
:
153−792=cosA
According to this equation m∠A
is equal to the inverse cosine function of −153792
. Write this:
m∠A=cos−1(−153792)
Calculate the value of the inverse cosine −153792
on a calculator:
m∠A≈101°
Therefore, m∠A≈101°
.
6062 it is the correct answer
Katie has read 32%, so 32%=80 pages. To get the total number of pages, you have to divide 32 and 80 by 8 to get 4% and 10 pages. 4% of the book is 10 pages, and in order to get 100%, you have to multiply by 25(4*25=100) on both sides. Remember, what you do to one side, you do to the other side. That leaves you with 100% and 250 pages. The book is 250 pages long. If she has read 80 pages, you subtract 80 from 250 to find how many pages she has left to read. The difference is 170. Katie has 170 pages left to read.
By the intersecting chords theorem, you have
This should help you on how to get the zeros and the answer for the bottom question is A
