May 15, 2015

Students review the area formula for rectangles with rational side lengths and prove the area formula for anarbitrary rectangle.

Students use a square grid to estimate the area of a curved region using lower approximations, upperapproximations, and average approximations.

Teacher and Student versions of full lesson from engageNY

- Mathematics > General
- Mathematics > Geometry

- Grade 9
- Grade 10

Reason abstractly and quantitatively.

Construct viable arguments and critique the reasoning of others.

Model with mathematics.

Use appropriate tools strategically.

Attend to precision.

Give an informal argument for the formulas for the circumference of a circle, area of a circle, volume of a cylinder, pyramid, and cone.