CONST MASTER PRO TRIG - Trigonometric: Advanced construction math calculator with trigonometric functions for engineering and building professionals. Determine precise angle measurements and solve the most complex design and construction math problems. Built-in functions include stair calculations, common rafters, jack rafter key, circular key, and rake-wall key. Plus estimate board feet quickly. Features user preferences, exponential notation, backspace to change “justentered” values, constant operator, cost per unit, and paperless tape to review the last 20 entries. Operates as a standard math calculator. Includes protective hard cover, easy-to-follow user’s guide, pocket reference guide, English and Spanish “How-To” CD and user guides, long-life batteries, and full one-year warranty.