we know that
if 0 < θ < π/2
then
angle θ-------> belong to the first quadrant
so
sin θ and cos θ-----> are positive numbers
sin²θ+cos²=1---------> sin²θ=1-cos²θ-----> sin²θ=1-(0.707)²----> 0.50
sin²θ=0.50-----------> sin θ=0.707
the answer part A) is
sin θ=0.707
if sin θ= cos θ
then
θ=45°
Part B) find tan θ
tan θ=sin θ/cos θ--------> tan θ=0.707/0.707--------> tan θ=1
the answer Part B) is
tan θ=1