ACT Preparation / Unit 14 ACT 1301 short lesson, about 20 seconds
Rectangles and Triangles
Captions available
The idea
Perimeter is the distance around a figure; area is the space it covers, in square units. A rectangle's area is length times width; a triangle's is one half base times height.
In practice
A triangle with base 10 and height 6 has area ½ × 10 × 6 = 30 square units.
Where people slip
The height is perpendicular to the base, not a slanted side.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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