Question

solve it solution needed​

Answer 1

Given :-

• DE ⊥ AB

• DF ⊥ BC

• AB = 30cm

• DF = 12cm

• DE = 8cm

To find :-

• Length of BC

Solution :-

We know that to find the area of a parallelogram, we use the formula

Area of a Paralellogram = Base × Height

Now, taking the paralleograms area with base AB and height DE.

= ar(ABCD) = bh

= ar(ABCD) = AB × DE

= ar(ABCD) = 30 × 8

= ar(ABCD) = 240cm² → 1

Now, we can also see that there is another pair of base and height. By using their values, we will try to find out BC

We already know that the area of ABCD is 240cm² so we substitute it in this formula

Here, BC is the base and DF is the height

= ar(ABCD) = bh

= ar(ABCD) = BC × DF

= 240 = BC × 12

= $\frac{240}{12}$

= BC

= BC = 20

∴BC = 20

Answer 2

$\sf\red{Area \: of \: parallelogram=Base × Height}$

$\implies$$\sf\red{A(ABCD)=b×h}$

$\implies$$\sf\red{A(ABCD)=AB×DE}$

$\implies$$\sf\red{A(ABCD)=30×8}$

$\implies$$\sf\red{A(ABCD)=240{cm}^{2}}$

Now,

$\implies$$\sf\red{A(ABCD)=b×h}$

$\implies$$\sf\red{A(ABCD)=BC×DF}$

$\implies$$\sf\red{240=BC×12}$

$\implies$$\sf\red{BC=\frac{240}{12}}$

$\implies$$\sf\red{BC=20}$