Question

find the area of the following polygons ​

Answer 1

Step-by-step explanation:

Given:

AB=40cm

BC=28cm

CD=15cm

DA=9cm

angle DAB= 90°

angle BCD= 90°

To find:

Area( polygon ABCD)

Construction:

Draw a diagonal DB.

Proof:

∆DAB is a right - angled triangle.

∆BCD is a right angled triangle. .....

(Given& Construction)

Area of (∆DAB) = 1/2(base×height)

=1/2(DA×AB)

=1/2(9×40)cm

= (9×20)cm

= 180 cm^2 ..... (1)

Area of (∆BCD)= 1/2(base×height)

=1/2(DC ×CB)

= 1/2(15×28)cm

= (15×14 )cm

= 210 cm^2

therefore,

Area of ( polygon ABCD)=Area of

(∆DAB) +

Area of (∆BCD)

Area of (polygon ABCD)=(180+210)cm^2

..... [from(1)&(2)]

Area of ( polygon ABCD)= 390 cm^2

Answer 2

Answer:

Step-by-step explanation: