i have these 3 exercises

mathe25

Junior Member
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Oct 13, 2011
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22112011027.jpgi have these 3 exercise.
at first ex.i have to prove (confirm) that the formule its true.
at the 2 i have to find S.we have circular arc too.:eek:
at the third i have to find S too...we have 2 diagonals...can someone help me,please
 
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Please do not post exercises without asking any questions of your own. (See the post titled "Read Before Posting" for guidelines on what to post.)

We like to see what you've thought about or tried thus far. Only then can we determine where to begin helping you.



There are a few different ways to prove Heron's formula. HERE are google search results. THIS PAGE provides a concise proof using some basic trigonometric identities.




The area of the shaded region in exercise 2 is obtained by subtracting the area of the circular sector from the area of the triangle.

Have you learned yet how to use the formula for calculating the area of a circular segment? You'll need to first determine the central angle.




In exercise 3, they've given you the base and hypotenuse of a right triangle. Use the Pythagorean formula to get the height. After you have an expression for the height, use the famous formula for the area of a triangle to finish.




Not sure what else to say, at this point. If you would like more help, please be specific. Cheers :cool:
 
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