Question

Perimeter of the trapezium ABCD is 18cm such that parallel sides are 4cm and 8cm and non parallel sides are equal. Find the area of the trapezium ABCD​

Answer 1

Answer:

Step-by-step explanation:

let equal sides be = x cm

paralel sides are = 4,8

perimeter = 18 cm

so non parallel sides

x+x+4+8 = 18 cm

2x = 18- 12

2x = 6

x= 3 cm

now

height can be found by using pythogoras theorem

but for that

we have to subtract non parallel sides from each other

8-4=4

now divide it by two as this will be two bases of two right triangles

4/2 =2

now consider non parallel side as hypotaneus

so height will be perpendicular side which can be found by

3^2 =2^2 +height ^2

9-4= height^2

5 = height ^2

height = _/5

now area of trapezium

= 0.5(sum of parallel sides)(height)

= 0.5( 12)(_/5)

= 6_/5 cm^2 answer