Unit 10 · Measurement and Three-Dimensional Geometry

10.1Perimeter and Area of Basic Figures

Quick Answer

Perimeter is the total distance around a figure. Area is the measure of the region enclosed. Key formulas: rectangle A = lw, parallelogram A = bh, triangle A = ½bh, trapezoid A = ½(b₁+b₂)h, circle A = πr².

Essential Question

How do the area formulas for all basic plane figures relate to the fundamental rectangle formula A = bh?

Learning Goals

  • 1State and apply perimeter formulas for common polygons.
  • 2State and apply area formulas for rectangles, parallelograms, triangles, and trapezoids.
  • 3State and apply circumference and area formulas for circles.
  • 4Choose the correct formula for a given figure.

Key Vocabulary

Perimeter

The total length of the boundary of a two-dimensional figure.

Area

The number of square units needed to cover a two-dimensional figure.

Height (of a polygon)

The perpendicular distance between the base and the opposite side or vertex.

Full lesson content coming soon

Worked examples, guided practice problems, a workbook, quiz, and downloadable PDF resources will be added to this lesson in Phase 2. The learning goals and vocabulary above reflect the complete lesson scope.