中2數學~幫幫忙~thz

1) [(13-8)^2+(12)^2]^1/2
=13m

2)a)[(15)^2+(20)^2]^1/2
=25km

b)25km/(50km/h)
=0.5hour

3)a)10.64*5/60
=0.887

b)10.64*5/60
=0.9

(1)
The difference between the top of poles
= [ (13 - 8)^2 + 12^2] ^ (1/2) (Pyth. Thm.)
= (5^2 + 12^2) ^ (1/2)
= 169 ^ (1/2)
= 13m

(2a)
Distance from the starting point
= (15^2+20^2)^(1/2)
= 625^(1/2)
= 25km

(2b)
Time to complete
= (15+20) / 50
= 0.7 hour
= 42 min.

(3)
Change in 5 min
=10.64 C / 60 min x 5 min
= 0.8866666666666666666667 C

(a) 0.887
(b) 0.9

1)Two vertical poles are 8m and 13m high respectively.They are 12 m apart.Find the distance between the top of the poles.
>>>>>(the distance)^2 = [ (13-8)^2 + 12^2]

((((((c^2 = b^2 + a^2))))))))

2)A car starts from P,it runs 15km due south and then 20 km due west to reach Q.
a)Find its distance from the starting pont.
>>>>>>>>>同上面一樣!!!!((((((c^2 = b^2 + a^2))))))))自己draw a 圖出來就可以做到ga la~
>>>>>(the distance)^2 = [ (15)^2 + 20^2]

b)If the speed of the car is 50km/h,how long does it take for the car to complete the journey?
>>>>>>>>(15 + 20)/15
>>>>>>>>行左幾多,,再除以個speed>>>>>係一條要識ge equation>>>remember it!!!

3)The temperature in a room rose 10.64 degree Celsius in one hour.f the rise was uniform,what was the change of temperature in 5 minutes?
>>>>>>>>(10.64 / 60 ) * 5 = 0.88666666666666
>>>>>>>>first find 一分鐘 會升幾多度,,再 times 你要幾多分鐘

a)Correct your answer to 3 sig.fig.
>>>>0.887(to 3 sig.fig)>>>>>>四捨五入!!!!
b)Correct your answer to 1 d.p.
>>>>0.9(to 1 d.p.)

(a) & (b) 係進位的問題>>>>要識!!!!!
當然要明佢咩意思la~

work hard!!!