# Pi Formula

Visual definition of Pi (3.14), diameter, radius, and other circle vocab, as well as visual aides in learning math formulas for circles.

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Celebrate Pi Day with this linear equation graphing activity. Students are given a list of linear equations each with a corresponding domain or range. The equations will occur in either standard form or slope-intercept form. When the students graph all of the equations, they will have a picture of the symbol "Pi."

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Quadratic Expression, Quadratic Equation, Quadratic Formula - Math Classroom Poster by PosterEnvy, http://www.amazon.com/dp/B008NO6ZEK/ref=cm_sw_r_pi_dp_4klvrb0KC55AE

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In this collaborative activity celebrating Pi Day, students work with the circle formulas to find area, circumference, radius and diameter. Each pennant also includes a Fun Fact that students can read as they complete their circle problems. Once a pennant is complete, it can be hung along a string in your classroom to celebrate Pi Day!

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This is a fun song to sing on Pi Day and will liven up any Pi Day Celbration. It is to the tune of the "With a Little Help From My Friends" Made famous by the Beatles-- It can also be used when studying volume and surface area formulas for cylinders and spheres.

Euler's identity seems baffling: $$e^{i\pi} = -1$$ It emerges from a more general formula: $$ e^{ix} = \cos(x) + i \sin(x)$$ Yowza -- we're relating an _imaginary exponent_ to sine and cosine! And somehow plugging in pi gives -1? Could this ever be intuitive? Not according to 1800s mathematician Benjamin Peirce: > It is absolutely paradoxical; we cannot understand it, and

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