Area of a circle trigonometry, uses the coarea formula. Define a function formula_10 by formula_11. Note ρ is a Lipschitz function whose gradient is a unit vector formula_12 (almost everywhere). Let "D" be the disc formula_13 in formula_14. We will show that formula_15, where formula_16 is the two-dimensional Lebesgue measure in formula_14. We shall assume that the one-dimensional Hausdorff measure of the circle formula_18 is formula_19, the circumference of the circle of radius "r". (This can be taken as the definition of circumference.) Then, by the coarea formula, Similar to the onion proof outlined above, we could exploit calculus in a different way in
The Play That Goes Wrong 27 previews. A touring production began in Australia at the Comedy Theatre in Melbourne from February 2017, before heading to Adelaide, Sydney, Canberra, Brisbane and Perth. The play is touring North America, starting in September 2018 in Pittsburgh, Pennsylvania. "The Play That Goes Wrong" received positive reviews. Quentin Letts of the "Daily Mail" gave it five stars out of five, saying "As it all goes awry it becomes hard not to gas yourself with laughter. At one point I feared I was going to hyperventilate." Tim Walker of "The Telegraph" gave it four out of five stars and called it