Area of a trapezium — Mensuration Aptitude Question
Area of a trapezium: What is the area of a trapezium whose parallel sides are 20 cm and 12 cm and whose height is… Answer and worked solution on CodeKairo.
- Topic: Mensuration
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 45 seconds
Question
What is the area of a trapezium whose parallel sides are 20 cm and 12 cm and whose height is 10 cm?
Options
- 120 cm²
- 150 cm²
- 160 cm²
- 200 cm²
Show the answer and the worked solution
Correct answer: C. 160 cm²
Worked solution
- Area = ½ × (20 + 12) × 10 = ½ × 320 = 160 cm².
Answer: 160 cm².
The idea
Average the two parallel sides and multiply by the height. Using only one of the parallel sides is the usual error.
Shortcut. Split it into a 12 × 10 rectangle (120) and side triangles with a combined base of 8 (½ × 8 × 10 = 40): 160.
Common trap. 200 cm² — multiplying the longer parallel side by the height (20 × 10), as if it were a rectangle.