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A piece of rectangular paper with a length of 5cm and a width of 4cm is rotated around its length and width respectively to form two cylinders. Which cylinder has the largest volume should be estimated first and then calculated
Around the long,
A rectangle is 10 cm long and 3 cm wide. If you rotate the rectangle around its width axis, what is the volume of the cylinder?
14 × 102 × 3 = 3. 14 × 100 × 3 = 942 (cm3) a: the volume of the cylinder is 942 cm3
In the parallelogram ABCD, M is the midpoint of AB, BM = cm, and ABCD is a rectangle
Is there something wrong with your title
If BM = cm, then angle B and angle BCM in triangle CMB are equal = 90 degrees
Wrong?
M is a point on the parallelogram ABCD, BM = cm, proving rectangle ABCD?
If M is not the midpoint of AD, can we find it?
Proof: take the midpoint n of BC and connect Mn
Because BM = cm
Therefore, BNC is an isosceles triangle, Mn is the height on the bottom BC, and Mn is perpendicular to BC
Because m, n are the midpoint of the parallelogram ABCD,
So AB / / Mn / CD,
Because Mn is perpendicular to BC, AB and CD are perpendicular to BC
The parallelogram ABCD is a rectangle
If M is not the midpoint, it cannot be proved
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