mathermatic
2006-11-09 1:37 am
A square is inside a circle and the radius of the circle is 7 cm . Find the area of the square.
回答 (5)
2006-11-09 1:45 am
✔ 最佳答案
diagonal of the square = the diameter of the circleso diagonal of the square is 14cm
let the side of the square = x
By the Pythagoras theorem,
x²+x²=14
x²=7
x=√7
the area of the square=x²=7cm²
2006-11-09 2:37 am
Since the square is inside a circle,
therefore the diameter of the circle would be the diagonal of the square.
The radius of the circle is 7cm.
Then the diameter of the circle is 14cm and the diagonal of the square is 14cm.
Let the side of the square = x
Use the Pythagoras theorem,
x²+x²=14²
2x²=196
x²=98
x=√98
Therefore the area of the square=x²=98cm²
therefore the diameter of the circle would be the diagonal of the square.
The radius of the circle is 7cm.
Then the diameter of the circle is 14cm and the diagonal of the square is 14cm.
Let the side of the square = x
Use the Pythagoras theorem,
x²+x²=14²
2x²=196
x²=98
x=√98
Therefore the area of the square=x²=98cm²
2006-11-09 1:59 am
the radius of the circle is 7 cm, so the diagonal of the square is 14cm.
cut the square to two triangles in the diagonal. the base of triangle 14cm ( diagonal ) and the high of the triangle is 7cm ( half of diagonal ).
so the area of the triangle: base * high / 2
= 14 * 7 /2
= 49 cm^2
however, the sum of area of two triangles is equal to the area of square. so the area of the square is:
49 * 2 cm^2
= 98 cm^2#
OK?
cut the square to two triangles in the diagonal. the base of triangle 14cm ( diagonal ) and the high of the triangle is 7cm ( half of diagonal ).
so the area of the triangle: base * high / 2
= 14 * 7 /2
= 49 cm^2
however, the sum of area of two triangles is equal to the area of square. so the area of the square is:
49 * 2 cm^2
= 98 cm^2#
OK?
2006-11-09 1:54 am
(7x2)x(7x2)
=14x14
=196
the square is 196cm²
*the circle 's radius is 7 cm ,so the
square long 7x2 cm ,longxlong=cm²
,so (7x2)x(7x2)=the cm²
=14x14
=196
the square is 196cm²
*the circle 's radius is 7 cm ,so the
square long 7x2 cm ,longxlong=cm²
,so (7x2)x(7x2)=the cm²
參考: me
2006-11-09 1:51 am
When a circle's radius is 7cm, the diameter is 7x2 = 14cm
therefore, the diagonal of the square is 14cm,
let's assume the edge of the square is 'a'
hence, a^2+a^2 = 14^2
=> sa^2=196
=> a^2= 98
for the area of the square
the equation is a^2, from the previous equation, we know that a^2=98
therefore, the area is 98 units
therefore, the diagonal of the square is 14cm,
let's assume the edge of the square is 'a'
hence, a^2+a^2 = 14^2
=> sa^2=196
=> a^2= 98
for the area of the square
the equation is a^2, from the previous equation, we know that a^2=98
therefore, the area is 98 units
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