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The lengths of three sides of a right triangle are 12cm, 16cm and 20cm respectively. How many centimeters is the height of the hypotenuse of the right triangle? The solution of the equation
Let the height of the hypotenuse be X,
12 * 16 * 1 / 2 = 20 * x * 1 / 2
x=9.6
The length of three sides of a right triangle is 20cm, 16cm and 12cm respectively. Its perimeter is () cm and its area is () square cm?
48cm
96cm2
For rectangle, square and circle with equal perimeter, whose area is the largest and whose area is the smallest? Please use calculation to explain
The circle has the largest area
Rectangle has the smallest area
For the sake of simplicity, we assume that the perimeter is 16, then the area of circle is 3.14 * (16 / 6.28) * (16 / 6.28) = 20.38, the area of square is 16, and the area of rectangle is 15, so the area of circle is the largest and that of rectangle is the smallest
If the side length of a square is reduced by 3cm, the area is reduced by 15cm
Fang Chengjie
The side length x of a square
x²-(x-3)²=15
x²-x²+6x-9=15
6x=15+9
6x=24
x=4
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