The area of square ABCD is 200 square centimeters. Find the area of inscribed circle (π = 3.14)

The area of square ABCD is 200 square centimeters. Find the area of inscribed circle (π = 3.14)

50π

If the radius of inscribed circle ⊙ o of square ABCD is 3, the area of square ABCD is --

The radius of ∵ inscribed circle ⊙ o is 3
｜ diameter = 3 × 2 = 6 = side length of square
S positive = 6 ^ 2 = 36
If the radius of inscribed circle ⊙ o of square ABCD is 3, the area of square ABCD is 36

Two perfectly coincident square pieces of paper, ABCD and a1b1c1d1, with a side length of 4cm, in which ABCD is translated 3cm along the Ba direction, and the overlapping area after translation is calculated

4*（4-3）=4

In the cube abcd-a1b1c1d1 with edge length 1, point m is the midpoint of edge Aa1 and point O is the midpoint of edge BD1
1. Verify the OM vertical plane bdd1b12. Calculate the dihedral angle (acute angle) cosine value of bd1m and ABCD

1. In plane bd1m, if all the side lengths are known, OM ⊥ BD1 can be proved. Similarly, OM ⊥ db1. So om ⊥ plane bdd1b12. Extend d1m to P, so that PM = d1m, then p is on the straight line ad. thus, the intersection of two planes is Pb