90/2 = 45
45/1700 = 0.02647
0.02647 x 100 = 2.64
2.46%
There's many properties you can use to find an unknown angle.
There are too many to lists but one core example would be an isosceles triangle that has two adjacent sides and angles.
Let's say that the sides of an isosceles triangle are any number "x"
now since two sides of the triangle are the same we can add these two x's together.
x+x = 2x
now the other side of the triangle can be anything you like. We can call it 4x for this example.
now if we add them all together we'll get 4x+2x=6x
Now since the angles of a triangle add up to 180 degrees
we can equate 6x=180 leaving x to be 30.
Now since x belongs to both sides of the triangle we can say that both angles are congruent as well because the two sides of the triangle are congruent. This is a known triangle law.
Since both angles are now 30 degrees this will leave us with 2(30) = 60
now if we subtract 180 - 60 we'll get 120 which is the remainder of the 3rd angle of the side that corresponds with 4x.
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Answer:
OK, lets start by drawing a basic graph (the first one) so we can visualize.
We already know that the y coordinate of the circle's center is 
.
We know that the circle is tangent to the 
axis at 
That means the x coordinate of the center has to be 
, as the tangent is a point on the edge of the circle that touches a line at exactly one point.
The radius is the distance from the center of the circle to its edge. We know the center's location now, it is 
and a point on the edge of the circle (the tangent point) which is . so the distance between the points is 4 which is the radius (you can use the distance formula, but it's quite oblivious.)
We can imagine the circle should look like this (the second one):
Now we can piece together an equation
The equation of a circle is 
where 
is the center and 
is the radius. When we put the numbers in: we get 
which can be simplified into which is the answer.
Step-by-step explanation:
