Pythagorean Theorem
c² = a² + b²
Triangle Area Formula
Area = Base × Height ÷ 2
Triangle Perimeter
Perimeter = a + b + c
Equilateral Triangle
Area = (√3/4) × a²Height = (√3/2) × a
Isosceles Triangle
Area = (b/4) × √(4a² - b²)
Heron's Formula
S = √[s(s-a)(s-b)(s-c)]where s = (a+b+c)/2
Triangle Type Classification
Classify triangle based on side lengths