#1**+10 **

The whole circumference is given by 2*pi*25. The shorter arc length from B to C is the fraction 144/360 of the whole circumference (because there are 360° needed to go all the way around the circumference, and you just want to go 144° around), namely:

$${\frac{{\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{\pi}}{\mathtt{\,\times\,}}{\mathtt{25}}{\mathtt{\,\times\,}}{\mathtt{144}}}{{\mathtt{360}}}} = {\mathtt{62.831\: \!853\: \!071\: \!795\: \!864\: \!8}}$$

or ≈ 62.8

Alan Jul 11, 2014

#1**+10 **

Best Answer

The whole circumference is given by 2*pi*25. The shorter arc length from B to C is the fraction 144/360 of the whole circumference (because there are 360° needed to go all the way around the circumference, and you just want to go 144° around), namely:

$${\frac{{\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{\pi}}{\mathtt{\,\times\,}}{\mathtt{25}}{\mathtt{\,\times\,}}{\mathtt{144}}}{{\mathtt{360}}}} = {\mathtt{62.831\: \!853\: \!071\: \!795\: \!864\: \!8}}$$

or ≈ 62.8

Alan Jul 11, 2014