Question

A parallelogram has sides 34 cm and 20 cm. One of its diagonals is 42 cm. Calculate its area​

Answer 1

Step-by-step explanation:

REF.image

Area of triangle =

S(S−a)(S−b)(S−c)

( Here, S is the semi-perimeter)

S=

2

a+b+c

⇒S=

2

42+20+34

⇒S=

2

96

⇒S=48cm

Area of ΔABC=

48(48−34)(48−20)(48−42)

=

48×14×28×6

=336 cm

2

Now,

Area of parallelogram = 2× Area of ΔABC

=2×336

=627cm

2

Answer 2

Answer:

hope u got it frnds

Step-by-step explanation:

Area of triangle =

S(S−a)(S−b)(S−c)

( Here, S is the semi-perimeter)

S=

2

a+b+c

⇒S=

2

42+20+34

⇒S=

2

96

⇒S=48cm

Area of ΔABC=

48(48−34)(48−20)(48−42)

=

48×14×28×6

=336 cm

2

Now,

Area of parallelogram = 2× Area of ΔABC

=2×336

=627cm

2

∴ so, the answer is B. 672cm

2

or 672 sq.cm