Question

que19 as fst as u can ​

Answer 1

Answer:

Sketch a paralellogram ABCD. Let AB = CD = 30 cm and BC = AD = 20 cm.

One of the diagonals is 40 cm. Let AC = 40 cm.

In △ABC, we know all the three sides. Use the cosine rule to find ∠ABC

cos(∠ABC) =AB2+BC2−AC22⋅AB⋅AC

Since the adjacent angles in a parallelogram are supplementary (1800), ∠BCD =1800−∠ABC

Now, if you use Cosine rule in △BCD, you can find the length of other diagonal.

cos(∠BCD) =BC2+CD2−BD22⋅BC⋅BD

Step-by-step explanation:

Answer 2

Answer:

10sqrt10

Step-by-step explanation:

Two side of length of parallelogram = 30cm and 20 cm

one side of diagonal = 40cm

Since diagonal intersect each other

so

by appollgus theorem

30^2 + 20^2= 2*20^2 + 2*x^2

1300 = 800+2x^2

500= 2x^2

250 = x^2

x = 5sqrt10

so

side of diagonal = 2x = 10sqrt10