Step by step
The question
Question: find the height of a parallelogram with area 54 cm² and base 9 cm.
1 Use the rule
The height goes straight up from the base.
It makes a right angle with the base.
We know the area, so we start from the area rule.
Remember: move the end triangle and it is a rectangle.
So the area is base times height: A = b × h.
Now put the numbers in: A = 54 and b = 9.
9 times h is written 9h.
Let's swap the two sides, so h is on the left.
2 Remove the 9
9h means 9 times h.
We want just h.
To remove times 9, we divide by 9.
We do it on both sides.
Why both sides?
The = sign means both sides are the same amount.
If we change only one side, they are not the same any more.
9 divided by 9 is 1.
So just h is left.
54 divided by 9 is 6.
So h = 6!
3 Check
Let's check: put h = 6 back in the area rule.
We get 54, the area in the question.
So the height is 6 cm.
Let's look back.
First: use the rule.
Then: remove the 9.
Last: check.