Geometry formulas for area and perimeter of shapes

Isosceles triangle

Isosceles triangle
$$\textbf{Area of the isosceles triangle}$$
$$A = \frac{1}{2} h a$$Calcular
$$\textbf{or}$$
$$A = \sqrt{s (s - a) (s - b) (s - b)} ,$$
$$ s =\frac{a + 2 b}{2}$$Calcular
$$\textbf{Perimeter of the triangle}$$
$$P = a + 2 b$$Calcular