Sin θ = 2 / 7
tan θ > 0
cos θ = ?
sin θ = opposite / hypotenuse
tan θ = opposite / adjacent
cos θ = adjacent / hypotenuse
short leg = opposite = 2
hypotenuse = 7
long leg = adjacent = ?
adjacent = √(7² - 2²)
adjacent = √(49 - 4)
adjacent = √45
adjacent = √9 * 5
adjacent = 3 √5
cos θ = adjacent / hypotenuse
cos θ = 3√5 / 7
