Answer:



Step-by-step explanation:
Represent:
- The opposite with a
- The adjacent with b
- The hypotenuse with c
Given that:


Required
Solve for a, b and c

So, we have:

Subtract 1 from both sides


Apply Pythagoras Theorem

Substitute 3 + 3b for a and 4 + 3b for c

Open brackets


Collect Like Terms


Expand

Factorize:


Split:


But the adjacent of a triangle can't have a negative measurement.
So:

Recall that:


Substitute 7 for b in the above expressions






Hence, the dimensions of the triangle are:



The answer to your question is b
The answer is D) 9 m.
Hope this helps! :)