c) $\text{cos}~37^{\circ}=\dfrac{y}{12}$ $y=12\cdot\text{cos}~37^{\circ}$ $y=9,58$ $a=\dfrac{x}{2}$ Pelo Teorema de Pitágoras, $a=\sqrt{12^2-y^2}=11,59$ $x=2a=23,18$ f) Cateto menor do triângulo = $\dfrac{15-6}{2}=4,5$ $\text{tg}~63=\dfrac{y}{4,5}$ $y=4,5\cdot\text{tg}~63$ $y=8,83$ $x=\sqrt{(4,5)^2+y^2}=9,91$