Gr 10 geometry Help Please

[TH1]

I need help with these 3 analytical geometry questions

1. A rock dropped out into a pond sends out a circular ripple whose radius increases steadily at 6 cm/s. A toy boat floating on the ponds is 2m east and 1 m north of the spot where the rock is dropped How long does it take for the ripple to reach the boat?
Here is my work for it
Convert the 2m and 1m into cm units
2m= 200cm 1m= 100cm To have a total of 300 cm
speed of ripple = 6cm/s
300/6 = 50 So it would take 50 seconds for the ripple to reach the boat

For this one I had no idea what to do for it and where to start since geometry is really hard for me
A truck with a wide load, proceeding along a secondary road is approaching a tunnel with a semicircular cross section and a maximum height of 5.25m. If the load is 8m high and 3.5m high will it fit through the tunnel? Explain your answer and include your calculations.

An error has been made in setting out the square base of a building. the coordinates listed for the corners of the squares are (60,20), (90,120), (-10,140) and (-40,50). Which coordinate pair is incorrect? Explain your choice. What should the coordinates be ? Write a paragraph explaining what the error is, how it was detected, and how it should be corrected.
I was going to plot it but I cant since the is not enough room on graph paper and i dont know what else to do

 

[galactus]

I thought we were having fun with these on mathhelpforum.

 

[Denis]

An error has been made in setting out the square base of a building. the coordinates listed for the corners of the squares are (60,20), (90,120), (-10,140) and (-40,50).

I was going to plot it but I cant since the is not enough room on graph paper and i dont know what else to do

Geesh....If they "don't fit" as is, then divide them all by 10 :idea:
(6,2), (9,12), (-1,14) and (-4,5) ; OK :?:

 

[Mrspi]

I need help with these 3 analytical geometry questions

1
An error has been made in setting out the square base of a building. the coordinates listed for the corners of the squares are (60,20), (90,120), (-10,140) and (-40,50). Which coordinate pair is incorrect? Explain your choice. What should the coordinates be ? Write a paragraph explaining what the error is, how it was detected, and how it should be corrected.
I was going to plot it but I cant since the is not enough room on graph paper and i dont know what else to do

If this is supposed to be a square, then all angles should be right angles, and all sides should be the same length.....

So....you don't need to graph this. Find the slope of the segments connecting the corner points which were given. What must be true about the slopes of perpendicular lines? I think if you do this, you'll find out which of the given points is in error.