Question

❣Ch 11 Mensuration Class 8 ❣

☺Question☺:
Length of fence of a trapezium shaped field ABCD is 120m .If BC = 48m ,CD = 17m and AD = 40 m ,find the area of this field .Side AB is perpendicular to the parallel side AD and BC

❤❤plz answer this fast .I want full explanation ❤❤​​

Answer 1

Question :-

Length of fence of a trapezium shaped field ABCD is 120m. If BC = 48m, CD = 17m and AD = 40 m, find the area of this field. Side AB is perpendicular to the parallel side AD and BC.

Solution :-

Given :-

• length of fence = perimeter of trapezium = 120 m
• BC = 48 m
• CD = 17 m
• AD = 40 m

To Find :-

• ar.( trap. ABCD )

Calculation :-

AB = [ perimeter - ( BC + CD + AD ) ] m

AB = [ 120 - ( 48 + 17 + 40 ) ] m

AB = [ 120 - 105 ] m

AB = 15 m

Now ,

$\begin{aligned} \small{ \sf{ar.(trap. \ ABCD) }}& = \dfrac{1}{2} \sf{ \times {\small{AB}} \times ( {\small{BC}} + {\small{AD}})} \\ \\ & = \dfrac{1}{2} \times 15 \times (48 + 40) \\ \\ & = \frac{15 \times \cancel{88} \ {}^{44} }{ \cancel{2} \ _{1} } \ \ {m}^{2} \\ \\ & = \ 660 \ \ {m}^{2} \end{aligned}$

Hence , the area of the trapezium-shaped field is 660 m² .