Explanation

Let's analyze the given circle equation:
$x^2+y^2=a^2$

This is the standard form of a circle with:

• Center at the origin $(0,0)$

• Radius $r=a$ (since $r^2=a^2$)

The diameter of a circle is twice the radius:

$$\text{<b><font color="\#0000ff">Diameter</font></b>}<b><font\; color="\#0000ff">=</font></b>\mathrm{<b><font\; color="\#0000ff">2</font></b>}<b><font\; color="\#0000ff">\times </font></b>\text{<b><font color="\#0000ff">radius</font></b>}<b><font\; color="\#0000ff">=</font></b>\mathrm{<b><font\; color="\#0000ff">2</font></b>}<b><font\; color="\#0000ff">\times </font></b>\mathrm{<b><font\; color="\#0000ff">a</font></b>}<b><font\; color="\#0000ff">=</font></b>\mathrm{<b><font\; color="\#0000ff">2</font></b>}\mathrm{<b><font\; color="\#0000ff">a</font></b>}$$

Explanation

In the first quadrant, all trigonometric functions, including sine and cosine, have positive values.

• Quadrant I:
  

  $\sin \theta >0$
  and
  

  $\cos \theta >0$
• Quadrant II:
  

  $\sin \theta >0$
  and
  

  $\cos \theta <0$
• Quadrant III:
  

  $\sin \theta <0$
  and
  

  $\cos \theta <0$
• Quadrant IV:
  

  $\sin \theta <0$
  and
  

  $\cos \theta >0$
  
  

Explanation

Because you are adding two negative numbers (

$\sin \left({200}^{\circ }\right)$

and

$\cos \left({200}^{\circ }\right)$

), the result will also be a negative number. 

Explanation

1 radian ≈ 57.3 degrees, based on the formula: 

1 radian = 180/𝜋 degrees.

It is a standard angular measurement in mathematics and physics.

Explanation

An isosceles triangle has two equal sides.

A consequence of having two equal sides is that the angles opposite those sides are also equal.