By the end of this lesson, you'll solve:
"A farmer has a trapezoidal field with parallel sides of 40m and 60m, and a height of 30m. How much land does he own?"
Area of a Triangle
Picture this: you cut a rectangle diagonally and get two equal triangles. The triangle is the simplest shape, and every other shape can be split into triangles!
Key Points
- 1Basic: Area = (1/2) x base x height
- 2Heron's: Area = sqrt[s(s-a)(s-b)(s-c)], where s = (a+b+c)/2
- 3s = semi-perimeter (half the total boundary)
- 4Use Heron's when you know all three sides but not the height
Pro Tip
Know the base and height? Use the basic formula. Only know the three sides? Use Heron's formula.
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