Question 77466: An arch is in the form of a circle and has a span of 30 meters and height 10 m. What is the radius of arc. Answer by 303795(602) (Show Source):
You can put this solution on YOUR website! Draw a diagram showing the arch and draw a vertical line at the middle of the arch and a horizontal line from one side of the arch to the other.
Place a dot on that vertical line to represent the centre of the circle and draw a line from that dot to one side of the arch.
The diagram should now have a right angle triangle with the right angle in the centre of the arch and pointing downwards.
The top horizontal part of the triangle will be 15 metres (half the width of the arch).
The hypotenuse (line to the edge of the arch) will be x and the vertical section will be x-10 because the top of the arch is 10 metres above the horizontal.
Using Pythagoras
=16.25 m
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