The arm of a steel crane is 62 feet long. When it is fully extended, the crane arm forms a 30 degree angle with a line parallel to the ground. How many feet above the ground is the top of the crane?

The top of the Crane is 31 feet above the ground.

Step-by-step explanation:

When it is fully extended, the crane arm forms a 30 degree angle with a line parallel to the ground. This means that a right angle triangle is formed. The length of the Crane's arm represents the hypotenuse. The horizontal distance represents the adjacent side of the right angle triangle. The distance, h of the top of the Crane from the ground represents the opposite side of the right angle triangle.

To determine h, we would apply

the Sine trigonometric ratio.

Sin θ, = opposite side/hypotenuse. Therefore,

Sin 30 = h/62

h = 62Sin30

h = 62 × 0.5

h = 31 feet

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb