Scalene Triangle Calculator Area via Heron for scalene. a b c Area 17.412 Step-by-step with your numbers: 1. Values used: 2. a = 5 3. b = 7 4. c = 9 5. Area = 17.412 Did we solve your problem today? 👍 Yes 👎 No Thanks for the feedback! All sides different. FAQ Obtuse? Heron works regardless. Related calculators Heron's Formula Calculator Find a triangle's area from its three sides. Area of a Triangle SSS Calculator Heron's formula alias.