Equation of a circle in standard form:
(x-h)²+(y-k)²=r²
r=radius
(h,k) is the center.

In this case:
(h,k) =(0,0) (h=0,k=0 )
r=4

Therefore:
(x-0)²+(y-0)²=4²
x²+y²=16

Answer: x²+y²=16

3 0

3 years ago

Prove that in each triangle the total angles are 180 degrees

dmitriy555 [2]

This is a proof that the angles in a triangle equal 180°:

The top line (that touches the top of the triangle) is
running parallel to the base of the triangle.

So:

angles A are the same angles B are the same

And you can easily see that A + C + B does a complete rotation from one side of the straight line to the other, or 180°

8 0

3 years ago

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Which of the following is the missing term of the geometric sequence in which a1= 2 and a3 = 200?

stellarik [79]

A2 = 20.
The formula is a(n+1) = 10a(n)

5 0

3 years ago

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