Question

plzz solve 33,35,36 and 38

Answer 1

33.Let a,b,c be the sides of the triangle.

Perimeter 2s = a + b + c
Semi-perimeter, s = (a+b+c)/2
Using Heron's formula:
Area of the triangle A = √s(s−a)(s−b)(s−c)

Now, if the sides are doubled: 2a, 2b, 2c

Let s' be the semi-perimeter.
2s' = 2a + 2b + 2c
s' = a + b + c
or s' = 2s

Area of the triangle, A' = √s′(s′−2a)(s′−2b)(s′−2c)
A' = √(2s)(2s−2a)(2s−2b)(2s−2c)
A' = √24s(s−a)(s−b)(s−c)
A' = 4√s(s−a)(s−b)(s−c)
A' = 4A
A':A = 4:1
Ratio of area of the new triangle and old triangle is 4:1

Answer 2

37] radius will be 2.1 cm
ball in shape of shpare
so the valume of shpare is
v =4×π×r³/3
v =4×22×(2.1)³/21
v =38.808 cm³

density = mass/valume
8.9 ×38.808 = mass
345.3912 gram = mass

38] hieght = h= 15cm

valume =1×π×r²×h
1570. = 1×22×r²×15
1570. = 330r²
1570/330=r²
4.75 = r²
√4.75 = r
2.17 = r

daimeter
= 2×radius
=2×2.17
=4.34 cm

36)Given, a river 3m deep and 40m wide is flowing at the rate of 2km per hour.

Area of cross section of the river = 3 * 40 = 120 m2

Now, volume of water flowing through this cross section in every minute = Area * rate

                                                                                                 = 120 * 2 km/hr

                                                                                                 = 120 * (2000/60) m/min

                                                                                                 = 2 * 2000

                                                                                                 = 4000 m3

Since 1 m3 = 1000 litres

So, 4000 m3 = 4000 * 1000 litres = 4000000 litres

So, in 1 minute, water will fall into the sea is 4000000 litres.