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Area of parallelogram base 12 m height 7 m

Step by step, with the reason for every step · Parallelogram and trapezoid · Geometry

Step by step

The question

Question: find the area of a parallelogram with base 12 m and height 7 m.

1 Make a rectangle

A parallelogram has two pairs of parallel sides.

It looks like a rectangle pushed over.

The height goes straight up from the base.

It makes a right angle with the base.

Cut off the triangle at the left end.

Move it to the right end.

It fits exactly.

Now it is a rectangle, 12 m long and 7 m high.

Nothing was added or lost, so the area is the same.

2 Base times height

So the area is base times height: A = b × h.

A = b × h

Now put the numbers in: b = 12 and h = 7.

A = 12 × 7

12 times 7 is 84.

So the area is 84 m².

A = 84 m2

3 Check

Let's check another way.

A line from corner to corner cuts it into two triangles.

Each triangle is half of base times height.

Both have base 12 and height 7.

12 × 12 × 7 + 12 × 12 × 7 = 42 + 42 = 84

We get 84 again.

So the area is right!

Let's look back.

First: make a rectangle.

Then: base times height.

Last: check.

Answer
A = 84 m2

Your turn

Try this one yourself, then check:

Find the area.
Show the answer
A = 143 m2

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