Question

Question No 6 and 7 from Parameter and Area...

Answer 1

HJ SNBS 1/2 ×16×x=40
=8x=40
x=40/8
diagnol=5

Answer 2

Given:

7)Rhombus diagonal=24cm long

Perimeter of rhombus =perimeter of equilateral triangle

Equilateral triangle side=20 cm long

ATQ---

Perimeter of equilateral triangle =3a
=3×20=60 cm^2

rhombus perimeter=4a

60=4a (because p of rhombus =p of equilateral triangle)

4a=60

a=60/4=15m

We have rhombus side now-----

rhombus diagonal bd=24(see the attachment)
1/2 of bd=12cm

Now wehave bo=12cm
=bc=15cm
=oc=x

As we know that rhombus diagonals bisect each other at 90°

Bc=hypotenuse
oc=height
ob=base

Now we use Pythagoras theory

Bc^2=oc^2+ob^2

15^2=x^2+12^2

225=x^2+144

x^2=225-144

x^2=81

x=9cm

we get oc=9cm but it is half of dialogonal so just double it we get the answer.

9×2=18cm

6)No. 6 can be made by Pythagoras theory by above method which ihave use to find 2nd diagonal.
do it yourself you can do it-Good luck.