Exercises for Programmers: 57 Challenges to Develop Your Coding Skills - Chapter 3, Paint a Room - Circle

Variation #2....do a circular room.  I find that to be less about coding and more about reminding myself of basic geometry.  It's less code than the square room in some respects.

Fiddle: https://jsfiddle.net/NodToNothing/7buham4g/
All Fiddles: https://jsfiddle.net/user/NodToNothing/fiddles/

JS Fiddle Code:
HTML: <div id="app"> <!-valiidity.valid -checks against the min during typing --> <!--https://www.w3schools.com/js/js_validation_api.asp--> Room Radius: <input min="0" ref="input" type="number" value="10" v-model="radius" oninput="validity.valid||(value='');"/><BR/> Paint coverage (square feet per gallon)a: <input min="0" ref="input" type="number" value="350" v-model="coverage" oninput="validity.valid||(value='');"/><BR/> <br>Square Feet: {{sqFeet}} <br>Gallons of Paint: {{gallons}} </div> Javascript + Vue 2.2.1 var app = new Vue({ el: '#app', components: { }, data: { radius: 10, coverage: 350 }, computed: { gallons: function(){ //return ((this.pizzas * this.slices) % this.people); //the disadvantage of f-ed up long math in line, you lose your place, that took a few iterations return Math.ceil((this.radius * 3.14 * this.radius) / this.coverage); }, sqFeet: function(){ return (this.radius * 3.14 * this.radius); } } })