Area Formulae Flashcards

All 6 cards in this deck

What is the formula for the area of a triangle?

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

What is the formula for the area of a parallelogram?

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

What is the formula for the area of a trapezium?

$A = \frac{1}{2}(a+b)h$, 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 parallelogram you multiply two adjacent side lengths.

False. You multiply the base by the perpendicular height, not by the slant side.

What are the steps to find the height of a triangle when its area and base are known?

e.g. area $24$ cm², base $6$ cm

1. Substitute into the formula: $24 = \frac{1}{2} \times 6 \times h$
2. Simplify: $3h = 24$
3. Divide: $h = 8$ cm

How many square centimetres are there in $1\text{ m}^2$?

$10\,000$, since $100 \times 100 = 10\,000$.