Polygon Area Calculator - Online Irregular Shape Tool
Calculate the area of an irregular polygon by entering its vertex coordinates. Uses the shoelace formula. Pure math.
UD5 Toolkit
Test your knowledge of area formulas for triangles, circles, rectangles, and trapezoids!
Enter the area in square units.
Calculate the area of an irregular polygon by entering its vertex coordinates. Uses the shoelace formula. Pure math.
Draw perfect ellipses by dragging focal points and a point on the curve. See the equation update dynamically. Educational.
Estimate make probability of a putt based on distance and skill rating. For disc golf enthusiasts. Fun statistical tool, no data upload.
Determine what score you need on your final exam to achieve your target overall grade. Enter current grade, weight, desired grade. Local only.
Try to draw a perfect circle freehand. Score based on roundness. Fun and addictive. No data sent.
Drag pie slices to represent fractions and see them added together. Great for visual learners.
Practice mental arithmetic with customizable operators and digit count. Timed rounds, score tracking. Works offline. Improve your brain speed.
Drag the seven tangram pieces to form a target silhouette. Multiple puzzles. Develop spatial thinking. All canvas interactions.
Solve random arithmetic problems under a time limit. Track your score and improve mental calculation. No data collected.
Complete a 10x10 multiplication grid against the clock. A fun way to master times tables.
Calculate board feet for dimensional lumber and generate a cut list with waste factor. Quick carpentry tool.
Click cells to see patterns, highlight multiples. Visual way to learn multiplication. Print empty grid.
Answer a series of deliberately confusing and trick questions. Lives system and funny wrong answers. Playful, no data stored.
Check if your A/B test results are statistically significant using chi-squared test. Enter visitors & conversions for control/variant. Results in plain English.
Test how fast you can convert between binary and decimal. Timed drills with increasing difficulty. Learn base‑2 fluency.
Generate a sheet of random arithmetic problems (+, -, ×, ÷) with configurable digits. For kids and brain training.
Calculate gear inches, meters of development, and speed ratio for any chainring/cog combination. For cyclists.
Select tuning, scale length, and string gauge to calculate total tension on the neck. Build custom string sets.
Enter roof line or tree height and get the length of light strings needed. Estimate power draw.
Enter number of eyelet pairs and lacing style to find the correct shoelace length in inches/cm. Never buy too short.
Enter pins per roll and calculate total bowling score including strikes and spares. Supports 10 frames. Learn scoring rules visually.
Show a word and guess the correct translation, but watch out for false friends. Avoid embarrassment.
Enter two names and get a playful love compatibility percentage. Purely for entertainment! All calculation happens instantly in your browser.
Type a mathematical expression like 'sqrt(16)+sin(pi/2)' and get the result instantly. Supports popular functions. Local.
Enter mold dimensions or water weight to get total resin needed, including Part A and B.
Measure window width and get rod length and number of curtain panels for proper fullness.
Measure a ring's inside diameter or circumference and convert to US, UK, European, and Japanese sizes.
Calculate output voltage from a two-resistor voltage divider. Enter input voltage and resistances to see Vout. Includes circuit schematic. No data sent.
Design circular string art by ticking nails and seeing simulated thread lines. Adjust number of nails and steps. Export pattern. Local only.
Calculate salt and water for a safe vegetable fermentation. Adjust for pepper weight. Visual brine guide.