In the circle below, DB = 22 cm, and m<DBC = 60°. Find BC. Ignore my handwriting.
1 answer:
Answer:
Step-by-step explanation:
step 1
Find the measure of the arc DC
we know that
The inscribed angle measures half of the arc comprising
substitute the values
step 2
Find the measure of arc BC
we know that
----> because the diameter BD divide the circle into two equal parts
step 3
Find the measure of angle BDC
we know that
The inscribed angle measures half of the arc comprising
substitute the values
therefore
The triangle DBC is a right triangle ---> 60°-30°-90°
step 4
Find the measure of BC
we know that
In the right triangle DBC
substitute the values
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Answer:
Number 3 is correct.
129.19m
Step-by-step explanation:
You might be wondering how did I got 32⁰, well, that's because they are alternate angles.
Now, we're trying to find the opposite side of the triangle.
Using the laws,
we got cos32⁰=x/243.8
243.8cos32⁰=x
129.19⁰
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Answer:
Step-by-step explanation:
We can use either angle, but I'm going to use the one on the bottom. So, in order to find x, we need to use tangent. One side we know is the adjacent, and the side we don't know is the opposite, therefore we need tangent. Here's the equation:
Obviously, we can't have a root in our denominator, so we need to get rid of it somehow. Here's how:
We multiply the denominator of the fraction by .
multiplied by itself is simply 2. Try it! We also want to multiply the numerator by
, but there isn't really a number we can use with that, so we'll just add it to the side. The equation you have now is:
Let's try to work this out now. Since the denominator is 2, we have to multiply both sides by it to find x.
We can plug 2 in for the x in the numerator now:
2 and 2 cancel out, so you get 1 in both the numerator and denominator. That's how we get our answer of
Also, because this is a 45-45-90 triangle, you don't really have to do all that work. If it's a 45-45-90 triangle, both legs should be the same length. :)