Option D is the correct answer.
Answer:
D. ∠B and ∠C are congruent.
Step-by-step explanation:
Since, ∠A and ∠B are supplementary.
Therefore,
∠A + ∠B = 180°.....(1)
Since, ∠A and ∠C are supplementary.
Therefore,
∠A + ∠C = 180°.....(2)
From equations (1) & (2)
∠A + ∠B = ∠A + ∠C
=> ∠B = ∠C
Hence, ∠B and ∠C are congruent.
If she deposited $600 and had $621.60 after four years, then she earned: $621.60 - $600 = $21.60 in four years. It means in one year she earned $21.60 ÷ 4 = $5.40. Now we have to find out how many percent of $600 is $5.40:
$5.40 = x% from $600
5.4 = x/100 * 600
5.4 = 600x/100 / * 100 (both sides)
540 = 600x / ÷ 600 (both sides)
x = 0.9
So the interest rate was 0.9% annually.
Now we have to find out how much is 0.9% from $1100:
$1100 * 0.9% =
= 1100 * 9/1009 =
= 9900/1000 =
= 9.9
It means in one year she would earn $9.90. After 7 years she would earn $9.90 * 7 = $69.30, so she would have in her account:
$1100 + $69.30 = <u>$1169.30</u>
Sin 3pi/4 is angle 135 degrees or 45 degrees below 180 degrees. Hence it's opposite side is 1 and adjacent is 1, implying the hypothenus is sqrt(2). Hence
Sin 3pi/4 = 1/sqrt(2). Now multiply by sqrt(2)/sqrt(2) to get:
[1/sqrt(2).] * [sqrt(2)/sqrt(2)] = sqrt2)/2
