Answer:
See Explanation
Step-by-step explanation:

80,000.
To round up to the nearest ten thousand, we would see if the next lower place value has a amount either 5 or higher or 4 or lower.
If it’s five or higher, we round up.
If it’s four or lower, we round down.
We can see that the number in the ten thousands place is 8. The number in the place value after 8 is 2.
2<5 so we round down.
The answer is 80,000.
Hope this helps!
In order to find the area for a strange shape, you divide it up into simpler figures. In this case, you already know that it can be divided into 4 triangles, so find the area of each triangle and add them up. Hope this helped!