Urgent i need a lamppost, cab, bent at point a after a storm. the tip of the lamppost touched the ground at point c, as shown below: triangle abc has measure of angle c equal to 45 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 12 feet. what is the height, in feet, of the portion ab of the lamppost?

The answer is 12 tan45°.

You can get the answer here by remembering SOHCAHTOA.

You know that you will use TOA based on the given.

Tanθ = Opposite/Adjacent

The angle is given and so is the adjacent. 

In this case:
θ =  45°
A = 12ft

Now all you need to do is input what you know into the equation:

Tanθ = O/A
Tan45° = O/12

You are looking for the opposite, so you just need to multiply both sides of the equation by 12 to isolate O no one side of the equation.

12 * Tan45° = 12 * O/12 

And you will then be left with

12Tan45° = O