I believe it’s AB AND DF, ZBAC = ZDEF
Andrew is wanting to build a slide for his daughter's tree house in the backyard. The tree house is approximately 5 feet off the ground and he wants the slide to have a 30 degree angle with the ground. He will need to by 10 ft of sliding board.
Answer:
Option A. 
Step-by-step explanation:
we know that
In the right triangle MNL
Applying the Pythagoras Theorem

substitute the values


Let's solve your equation step-by-step.
2b+1=16−3b
Step 1: Simplify both sides of the equation.
2b+1=16−3b
2b+1=16+−3b
2b+1=−3b+16
Step 2: Add 3b to both sides.
2b+1+3b=−3b+16+3b
5b+1=16
Step 3: Subtract 1 from both sides.
5b+1−1=16−1
5b=15
Step 4: Divide both sides by 5.
5b/5=15/5
<em>answer: b=3</em>