Lesson Plan

Compute the perimeter of any triangle given its three side lengths

Apply the area formula A = 1/2 * base * height to right triangles and general triangles, correctly identifying the perpendicular height

Find the height of a triangle using the Pythagorean theorem when the height is not directly provided (e.g., in isosceles or equilateral triangles)

Use the equilateral triangle shortcuts: h = ssqrt3/2 and A = s^2sqrt3/4

Compute the area of a triangle from vertex coordinates using the shoelace formula or rectangle-decomposition method

G 403. Compute the area and perimeter of triangles and rectangles in simple problems G 506. Compute the area of triangles and rectangles when one or more additional simple steps are required G 302. Compute the perimeter of polygons when all side lengths are given