2019 · Q96
Consider the following for the next three (03) items:
ABCD is a quadrilateral with AB = 9 cm, BC = 40 cm, CD = 28 cm, DA = 15 cm and angle ABC is a right-angle.
What is the area of triangle ADC?
Elementary MathematicsMensuration
- A126 cm²
- B124 cm²
- C122 cm²
- D120 cm²
Explanation
Triangle ADC has sides 15, 28, 41 with semiperimeter 42. By Heron's formula, area = √(42×(42−15)×(42−28)×(42−41)) = √(42×27×14×1) = √15876 = 126 cm^2.