It is known that the base of an isosceles triangle BC = 8cm and the waist AB = 10cm, then the height of the AC side is? But the answer is different,

It is known that the base of an isosceles triangle BC = 8cm and the waist AB = 10cm, then the height of the AC side is? But the answer is different,

Do am ⊥ BC through a
AB=AC
BM=CM=4
AM=2√21
Finding the height of AC edge by area
h×10=8×2√21
h=8√21/5

An isosceles triangle is 8cm in both sides and 10cm in the bottom

With the current primary school knowledge, should not solve this problem

It is known that the length of a rectangle is (2a-b) cm, and its width is (a-b) cm less than its length?
If the length of a rectangle is known to be (2a-b) and the width is less than the length (a-b), then the circumference of the rectangle is (2a-b)

Width = (2a-b) - (a-b) = a
Perimeter = [(2a-b) + a] * 2 = 6a-2b

The circumference of a rectangle is ACM, the ratio of length to width is 3:2, and the length is three fifths of a cm, right

Wrong
The length is 3 / 10 (CM)