Depends on the calculator you have at your disposal. If it's one of the TI-83 series, you can use the built-in 'fnint' function.
https://brownmath.com/ti83/integr.htm
Answer:
height = 12 cm
Step-by-step explanation:
Parallelogram 1:
Area = base *height = 20 * 15 = 300 sq. cm
Area of parallelogram 2 = area of parallelogram 1
25 * height = 300
height = 300/25
height = 12 cm
12 hours? If I'm wrong, sorry about that
