Answer:
A ≈ 615.75 cm squared
or 616cm squared when rounded off
Answer + Explanation:
let x be the measure of angle x
let y be the measure of angle y

Now, solve:
plug x = 24 + y into x + y = 180
24 + y + y = 180
24 + 2y = 180
2y = 156
y = 78
Now, plug this back into the equation x = 24 + 78
x = 102
3x - 18 = 42
3x = 42 + 18
3x = 60
x = 60/3
x = 20
RU is 34. To find the answer you can use a proportion. In this problem the proportion would be 60/51 = 40/x. You can then cross multiply giving you 51*40=60x. You can then solve for x which is your answer.