Question

in fig 6, ABCD is a parallelogram where, CE parallel to AB produced and BF parallel to AD.
i] if AB=20 cm, AD=16 CM and CE=10 cm, then find BF=?​

Answer 1

Answer:

1) $\large\boxed{BF=12.5\:cm}$

2) $\large\boxed{AD=21\:cm}$

Step-by-step explanation:

1) AB = 20cm, AD = 16cm, CE = 10cm, BF = ?

⇒   Area of parallelogram = 1/2 × base × altitude

⇒   Area = 1/2 × AB × CE

⇒   Area = 1/2 × 20cm × 10cm

⇒   Area = 100${cm}^{2}$

We can also write it as :-

⇒   Area of parallelogram= 1/2 × base × altitude

⇒   Area = 1/2 × AD × BF

⇒   Area = 1/2 × 16cm × BF

⇒   Area = 8BF cm

Equalize both of them :-

⇒   8BF cm = 100${cm}^{2}$

⇒   8BF = 100cm

⇒   BF = 12.5cm

$\large\boxed{BF=12.5\:cm}$

2) AB = 30cm, CE = 14cm, BF = 20cm, AD = ?

⇒   Area of parallelogram = 1/2 × base × altitude

⇒   Area = 1/2 × AB × CE

⇒   Area = 1/2 × 30cm × 14cm

⇒   Area = 210${cm}^{2}$

We can also write it as :-

⇒   Area of parallelogram= 1/2 × base × altitude

⇒   Area = 1/2 × AD × BF

⇒   Area = 1/2 × AD × 20cm

⇒   Area = 10AD cm

Equalize both of them

⇒ 10AD cm = 210${cm}^{2}$

⇒ 10AD = 210cm

⇒ AD = $\frac{210}{10} cm$

⇒ AD = 21 cm

$\large\boxed{AD=21\:cm}$

Hope it helps you❤️❤️❤️  

Answer 2

Answer:

hikwiw8wosjdidjdjdsisos9sissisjjdjxjddidiid