The perimeter of a quarter circle is 17.85 miles. What is the quarter circle’s radius?

8.1

Step-by-step explanation:

The perimeter of a circle means the circumference. In this question it says the perimeter of a quarter circle is 17.85 miles and we want to find the quarter circle’s radius.

We know that the perimeter of the quarter circle is 17.85 which means that the 2 radii and the circumference of the circle sum to 17.85.

The formula to work out the perimeter of a quarter circle is       . We can  form an equation to work out the radius so,

 =    17.85

→ Multiply everything by 2 to get rid of the fraction

4r + π = 35.7

→ Minus π from both sides to isolate 4r

4r = 32.55840735

→ Divide both sides by 4 to isolate 4

r = 8.139601837

The radius of the quarter circle is 8.1 miles to 1 decimal place

answer

a,b, and d

explanation

a reflection angle is more than

but less than;

an angle that measures

is a reflex angle.(true)

an angle that measures less than

is acute.(true)

provided we are considering angles greater or equal to zero.

an acute angle lies in the range.

an obtuse angle is less than 180° but more than 90°

an angle that measures 300° is obtuse (false)

an angle that measures 65° is an acute angle.(true)