Learn about angle axioms, how to calculate perimeters and areas, 3D geometry and much more.

学习角公理、如何计算周长和面积、三维几何等等。

The Earth's circumference has been calculated to be 40,075km.

地球的周长经过测量是40075公里。

Oh my god. The circumference of the femur is over a foot.

我的天啊。股骨周长超过一英尺。

Circumference over diameter! 7,9 then 3,2,3.

周长看直径！7，9然后3，2，3。

The Euclid spacecraft is 4.7 meters tall and 3.7 meters around.

欧几里得航天器高4.7米，周长3.7米。

To them pi is the ratio of a circle's circumference to its diameter.

对他们来说，π 是圆的周长与直径之比。

It's wider, or more technically, has a greater circumference at the Equator.

它更宽，或者更严格地说，在赤道有更大的周长。

Using this, he actually measured the circumference of the Earth, and he got it right 2,000 years ago.

利用这些，他准确地测量出地球的周长，并在2000年前就得到了正确的数据。

You spent the first 600 weeks of your life being a kid and 400 being a teenager.

你会花人生的前 600周当个小孩， 以及400周长成青年。

I mentioned that these thigh bones were 30 centimeters, a foot in circumference.

我提到过，这些大腿骨的周长是30厘米，也就是一英尺。

One baobab has been seen whose trunk was thirty feet in diameter and ninety-five in circumference.

人们还曾发现过一棵树干直径长三十英尺、周长九十五英尺的巨型猴面包树。

First, researchers took the circumference of 61 men's and women's biceps, measured their grip strength, and their height.

首先，研究人员测量了61名男女肱二头肌的周长，以及他们的握力和身高。

The 20-meter-long rocket, with a diameter of two meters, is smaller than other members of the Long March rocket series.

这艘长20米、周长2米的运载火箭要比其他长征系列火箭小一些。

And the circumference of this building is 183 meters.

而这座建筑的周长是183米。

It stood prominent six feet, and could not be less than sixteen in circumference.

它突出六英尺，周长不能小于十六。

But to get the circumference, you'd need measuring tape or a piece of string, unless there was a better way.

但要测量圆的周长，你就得用卷尺或绳子，除非有更好的办法。

This tree had small buds last week and they're slowly opening.

这棵树上周长了小芽，它们正在慢慢开放。

Either way, knowing the distance and the angle, and applying a little geometry, he calculated the circumference of the Earth.

不管怎样，只要知道距离和角度，再加上一点几何知识，他就能计算出地球的周长。

The perimeter of the pergola was about 100m.

凉亭的周长约100米。

The circumference of the femur is over a foot.

股骨的周长超过一英尺。