Find the area of the quadrilateral ABCD in which ab=5cm, bc=4.5cm, cd=3.5cm, da=4cm and ac=6.5cm

A(ABCD) ≈ 17.285 cm²

Step-by-step explanation:

A = √s(s - a)(s - b)(s - c)

s = (a + b + c)/2

a ; b ; c = the sides of the triangle

s = (AB + BC + AC)/2 = (5cm + 4.5cm + 6.5cm)/2 = 16cm/2 = 8 cm

A(ABC) = √8(8 - 5)(8 - 4.5)(8 - 6.5)

= √8×3×3.5×1.5

= √126

≈ 11.225 cm²

     2. A(ACD) = √s(s - AC)(s - CD)(s - AD)

s = (AC + CD + AD)/2 = (6.5cm + 3.5cm + 4cm)/2 = 14cm/2 = 7 cm

A(ACD) = √7(7 - 6.5)(7 - 3.5)(7 - 4)

= √7×0.5×3.5×3

= √36.75

≈ 6.060 cm²

     3. A(ABCD) = 11.225cm² + 6.060cm² = 17.285 cm²

c: lkllmn.

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