Hi, thank you for posting your question here at Brainly.
All you have to do to acquire the equation is to substitute the variables to the formula for A and simplify. Since A = 1/2*b*h and h = bsin(C), then A can be in terms of one variable only, which is b.
A = 1/2*b*bsin(c)
A = 1/2*b^2*sin(C)

P. S. The inequality sign changed or flipped when there's a negative figure involved.
Hope this helps. - M
84 is your awnser if i helped i hope im in fourth grade so dont judge
Answer:
A= 100+20h B=40h
Step-by-step explanation:
A=100+20h
B= 40h