Question

1. Sound can travel through​

Answer 1

Answer:

A=70cm

B=80cm

C=90cm

Semi-perimeter =

2

(70+80+90)

=

2

240

=120cm

Area of triangle =

s(s−a)(s−b)(s−c)

=

120(120−70)(120−80)(120−90)

=

120×50×40×30

=

4×3×10×5×10×3×10×4×10

=4×3×100

5

=1200×2.23

=1200×

100

223

=2676cm

2

∴ Area of triangle =2676cm

2The sides of a triangle are 70 cm, 80 cm and 90 cm. Find it area.

Answer 2

Answer:

Sound travels in waves.

Sound waves usually travel through air or water, but they can also travel through solids too, like walls or furniture. Sound waves use the matter to move the vibrations.

hope it will help you dear ☺️