An isosceles triangle has equal sides of length 5 cm each and a base of 8 cm. Using Heron's formula, its area is:

Answer as guest — Start Free Practice Test to earn Practice PointsHow to earn pointsAsk a question+3Answer a question+1Someone answers yours+1Your Q gets upvoted+1Pioneer bonus (first 5)+51 point = ₹1 discount on purchases, ask questions & climb the leaderboard!

• A 12 cm²
• B 24 cm²
• C 20 cm²
• D 6 cm²

Submit Answer

Show answer and explanation

Answer: A. 12 cm²

s = (5 + 5 + 8)/2 = 9 cm.
Area = √(9 × 4 × 4 × 1) = √144 = 12 cm².

Answering after opening this box earns no Practice Points.