Mathematics: A circle is subdivided by a central angle of 90 degrees. The length of the subtended arc is 25 mm. What is the radius of the circle?A: B: C: D:

you are to subtract the equation...

A circle is subdivided by a central angle of

Ответ:

marci30

18.04.2021

Mathematics

$(\text{A})\:\frac{50}{\pi}\:\text{mm}$

Step-by-step explanation:

This the arc is 90 degrees and there are 360 degrees in a circle, it makes up $\frac{90}{360}=\frac{1}{4}$ of the circle. Therefore, its length will be $\frac{1}{4}$ of the circumference. Since its length is 25 mm, the circumference is then $25\cdot 4=100\:\text{mm}$ . The circumference of a circle is given by $2\pi r$ , where is the radius of the circle. Therefore, we can set up the following equation and solve for :