Solution of two geometric math problems in the second day of junior high school.

1. According to Pythagorean theorem, the third right-angled side = below the root sign? Square of hypotenuse-square of right angle.

= Under the root sign? 10^2-8^2

∫S△= 65438+ 0/2 product of two right angles = 1/2 hypotenuse * height on hypotenuse.

Let the height on the hypotenuse be x? Centimeter,

Then 8*6= 10x.

The solution is x=4.8.

2. The analysis is as follows: waist circumference AC=AB, then AD=CD= 1/2AC.

DB = DB，C△ABD=AD+AB+DB，C△CBD=CD+CB+DB

There are two situations:

Let AB=X,

(1) If waist circumference is greater than hip circumference,

C△ABD-C△CBD=3

AB-CB=3

X-5=3

X=8

The test shows that when X=8, the sum of any two sides is greater than the third side, which is true.

(2) if the waist length is less than the bottom length.

C△CBD-C△ABD=3

CB-AB=3

5 X = 3

X=2

Test, when X=2, 2+2 < 5, this situation is not true.

A: Waist circumference is equal to 8.