The height of the fan is 8cm, the degree is 120, and the area is urgent, I want to sleep, and I will

Muhaha, the standard answer is here!

According to your idea, you can finally calculate the radius of the sector r=16sfan=nr2 360 (n is the degree of the central angle, r is the radius)sfan=x 120 x 256 360, and finally we get sfan=256 3

If you don't know how to calculate R, I can give you a picture Oh hehe.

Solution: The height of the bow is 8cm, the degree of the central angle of the circle is 120 ° extended to the center of the circle, and the right-angled side of the 30-degree angle in the right-angled triangle is equal to half of the hypotenuse, and the diameter of the circle is 16 cm.

The area of the sector is 1 3 16 and the area of the triangle is 1 2 8 16 -8 = 4 692

The area of the bow = 1 3 16 -4 692 Let's figure it out for yourself.

What is Sector Height? Typing it wrong, right?

If the radius is 8 cm, then the area is 8 120 360) = 3 64 (square centimeters).

The formula for the area of the fan: s= r2 (360° at the center of the circle).

Multiply by 8 squared and multiply by 120/360. The answer is 6/3 of a square centimeter.

It is a circle with a radius of 8cm, take one-third of it, because the whole circle is 360°, area =

There are two formulas.

1）s=1/2lr

2) s=n r square 360 = 80 degrees 5*5 cm 360 = square cm

The sector area formula n(pai)r 360

i.e. system: (

Find the area of the circle first, and then use the proportional calculation.

S fan = 5 2 * * 80 360) = squared.

Sector area = 80/360 multiplied by 25

The area of the sector is x120 360 times x=80 times 30x=720

A 120-degree fan is one-third of a circle, that is, one-third of a circle with a radius of 1 cm is 1 3 r*r