Answer:Part 1: x = 6.2Part 2: u = 3.46 and v = 2Part 3: Altitude = 5.196Step-by-step explanation:Part 1:From the given figure, we can write [tex]\cos 59 = \frac{x}{12}[/tex]⇒ x = 12 cos 59 = 6.18 ≈ 6.2 (Answer)Part 2:From the figure we can write [tex]\sin 60 = \frac{u}{4}[/tex]⇒ u = 4 sin 60 = 3.46 (Answer)And [tex]\cos 60 = \frac{v}{4}[/tex]⇒ v = 4 cos 60 = 2 (Answer)Part 3:Perimeter of the equilateral triangle is 18.So, if each side is a, then 3a = 18⇒ a = 6Now, if we draw an altitude to the equilateral triangle then it will bisect the base perpendicularly.If the altitude is x,Therefore, applying Pythagoras Theorem we get x² + 3² = 6² ⇒ x² = 27⇒ x = 5.169 (Answer)