If you mean 40% of the circle with the rotation at the center of the circle, then you do this:
Measure of circle: 360°
Amount of circle's measure: 40%
360 * 40% = 144°
Thus, to take up 40% of the circle you need to have an angle measure of 144°.
Answer: 2.55 (or 51/20) kilometers
Step-by-step explanation: 17/5 km per one hour is 51/20 (2.55) km per 3/4 hours
To write the given quadratic equation to its vertex form, we first form a perfect square.
x² - 2x + 5 = 0
Transpose the constant to other side of the equation,
x² - 2x = -5
Complete the square in the left side of the equation,
x² - 2x + (-2/1(2))² = -5 + (-2/1(2))²
Performed the operation,
x² - 2x + 1 = -5 + 1
Factor the left side of the equation,
(x - 1)² = -4
Thus, the vertex form of the equation is,
<em> (x-1)² + 4 = 0</em>