Push out: OC-OB=7

OC+OB+BC=58

The binary linear equation OC-OB=7 is obtained.

OC+OB=30

OC = 18.5 OB = 1 1.5

So two diagonal lines, one is 37 and the other is 23.

The second problem is the diagonal connection of 120 and 60.

Form four right-angled triangles with equal areas, Pythagorean theorem, and calculate that the length of two right-angled sides is twice as long as the root number 2, and the area of a small triangle is 4, so the diamond area is 16.

The third question shows that the side length is 10, and the diagonal lines are connected to form four identical right triangles. Pythagorean Theorem, 6,8, 10. Area is 6*8*0.5*4=96.

The fourth problem is that the length of binary linear equations is x and the width is y.

2(x+y)=8 x square +y square = 10, you can find xy! Usable area

The fifth question is too much trouble.