Question

find the area of quadrilateral ABCD in which AB=7cm BC=6cm CD=12cm DA=15cm and AC=9cm

Answer 1

hey mate...

2 answers · Mathematics
Best Answer
area of quadrilateral ABCD= Area of triangle ABC + Area of triangle ADC
Area of trianlge= sqrt(s(s-a)(s-b)(s-c))
FOR area of triangle ABC
s=(7+6+9)/2=11
area of triangle ABC=sqrt(11(11-7)(11-6)(11-9))
=sqrt(440)
= 20.9761
similarly,
area of triangle ADC=54

therefore area of quadrilateral ABCD=20.9761+ 54
=74.9761

ANOTHER WAY...

let it be 2 triangles rather than 1 big quadrilateral.

ABC = 7/6/9 and ADC = 15/12/9

total area
= √(11 * 4 * 5 * 2) + (12 * 9) / 2
= 2√110 + 54
= 74.976177
=~ 75 cm^2

Answer 2

Answer:

hope it was helpful to you

Step-by-step explanation:

let it be 2 triangles rather than 1 big quadrilateral.

ABC = 7/6/9 and ADC = 15/12/9

total area

= √(11 * 4 * 5 * 2) + (12 * 9) / 2

= 2√110 + 54

= 74.976177

=~ 75 cm^2