Question

Find the area of the given quadrilateral ABCD. Given that the length of BD, AE and BC are 28 cm, 20 cm, and 8 cm respectively.

• A. 392 $c{m}^2$
• B. 340 $c{m}^2$
• C. 784 $c{m}^2$
• D. None of these

Answer 1

The correct option is A

392 $c{m}^2$

It is given that DB = 28 cm, AE = 20 cm and BC = 8 cm
AE and BC are perpendicular to diagonal BD
Area of quadrilateral ABCD = Area of $\Delta$ ABD + Area of $\Delta$ BDC
= $\frac{1}{2}$ $\times$ DB $\times$ AE + $\frac{1}{2}$ $\times$ DB $\times$ BC
= $\frac{1}{2}$ $\times$ DB $\times$ (AE + BC)
= $\frac{1}{2}$ $\times$ 28 $\times$ (20 + 8)

=14 $\times$ 28
= 392 $c{m}^2$