Answer:
area of trapezium: -
formula...
½(sum of parallel sides)×height=area
=>240=½(12+x)×12
=>240=(12+x)×6
=>240=60+6x
=>6x=240-60
=>6x=180
=>x=180/6
=>x=30cm
therefore, the value of x is 30 cm.
Step-by-step explanation:
hope it helps u