SOLUTION: Heyy i really need some help on this question.. give me a hand pleasee. In a circle with radius 7cm, a chord is 3cm from the center. How long is another chord located 3 cm from

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Question 71137: Heyy i really need some help on this question.. give me a hand pleasee.
In a circle with radius 7cm, a chord is 3cm from the center. How long is another chord located 3 cm from the center?
Those are the choice of answers, could you please give me the steps of how to do it please!

A) 2 (root)10
B)7
C)4 (root)10
D)14

Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website!
Well, if I could draw the diagram it would be a whole easier, but I'll try to explain it in words so that you can draw the diagram:
1. Draw the circle a radius of 7 cm.
2. Mark a point 3 cm from the centre of the circle and draw a chord through it.
3. Connect the end-points of the chords with the centre of the circle.
You should now have an isosceles triangle inside the circle. The two equal sides of the triangle are just the radii of the circle so they are 7 cm. each and the base is just the diameter of the circle and that is 14 cm.
4. Draw a line from the centre of the circle perpendicular to the chord.
You should now see two congruent right triangles.
Focus on one of these. The height is 3 cm. and the hypotenuse is 7 cm. and the base is half the length of the chord.
Using the Pythagorean theorem, you can find the third side (call this x) of one of the right triangles.
x is one half the length of the chord so you will multiply this by 2 to get the entire length of the chord.
Simplify and solve for x.
Subtract 9 from both sides.
Take the square root of both sides.
This is half the length of the chord.
This is the length of the chord. Simplifying this, you gey:
Take the sqrt of 4 outside the radical as 2.