Question

I would like to know how to solve this & what the answer is?

Answer 1

step 1

Find out the circumference of the circle

`C=Pi*D`

where

D=2(4)=8 km ----> the diameter is two times the radius

substitute

`\begin{gathered} C=pi*8 \\ C=8pi\text{ km} \end{gathered}`

Remember that the circumference subtends a central angle of 360 degrees

so

Applying proportion

Find out the arc length by a central angle of 135 degrees

`\begin{gathered} (8pi)/(360^o)=(x)/(135^o) \\ \\ x=(8p\imaginaryI)/(360^(o))*135^o \end{gathered}`

x=3pi km

therefore

The answer is 3pi km