The area of quadrilateral is:

a) 5 cm²

b) 10 cm²

c) 11 cm²

d) 15 cm²

c

The correct answer is Option 3: c

Step 1: Area of Triangle ADC

• Base AC = 5 cm

• Height DE = 2 cm (as DE ⟂ AC)

• Area = ½ × base × height = ½ × 5 × 2 = 5 cm²

Step 2: Area of Triangle ABC

Sides given: AB = 4 cm, BC = 3 cm, AC = 5 cm

Check if it’s a right triangle:

• AB² + BC² = 4² + 3² = 16 + 9 = 25

• AC² = 5² = 25
  ⇒ Triangle ABC is a right-angled triangle at B

So, Area = ½ × AB × BC = ½ × 4 × 3 = 6 cm²

Step 3: Total Area of Quadrilateral ABCD

Area = Area of ΔADC + Area of ΔABC
= 5 cm² + 6 cm² = 11 cm²