Area Flashcards

All 6 cards in this deck

What is the formula for the area of a rectangle?

$\text{area} = \text{length} \times \text{width}$

What is the formula for the area of a triangle?

$\text{area} = \frac{1}{2} \times \text{base} \times \text{perpendicular height}$

What is the formula for the area of a parallelogram?

$\text{area} = \text{base} \times \text{perpendicular height}$

What is the formula for the area of a trapezium?

$\text{area} = \frac{1}{2}(a+b)h$, where $a$ and $b$ are the parallel sides and $h$ is the perpendicular distance between them.

True or false? To find the area of a triangle you multiply the base by a sloping side and halve it.

False. You must use the perpendicular height (the height at right angles to the base), not a sloping side.

How do you find the side length of a square from its area?

e.g. area $81$ cm$^2$

Take the square root of the area.

e.g. $\sqrt{81} = 9$ cm