Calculus Question (Really need help on this one!)

Question

Find the length of the arc of the polar curve r= sin² (∅/2) from ∅=0 to ∅= pi

Answer 1

r=sin²Φ/2 dr/dΦ =2sinΦ/2cosΦ/2•1/2 =sinΦ/2cosΦ/2 L=∫₀^π√(r² +(dr/dΦ)²)dΦ. So L=∫₀^π√(sin⁴Φ/2 +sin²Φ/2cos²Φ/2)dΦ. Then L= ∫₀^πsinΦ/2√(sin²Φ/2 +cos²Φ/2)dΦ L= ∫₀^π sinΦ/2 dΦ where the term in the square root is the trig identity. So L= -2cosΦ/2|₀^π and L=-2(0-1) =2.

Answer 2

I am measuring from 0,0 to 3.14,1.66.

a^2+b^2=c^2

2.75+9.87=12.63^2 so √=3.55=c