Mipango

Kikokotoo cha Eneo la Uso

Kokotoa eneo lote la uso wa mchemraba, mche mstatili, silinda, koni au tufe — kwa usahihi kwa π, kila sehemu ikionyeshwa.

Tokeo

Weka thamani kisha bonyeza Kokotoa ili kuona tokeo.

Fomula

Acuboid=2(lw+lh+wh)A_{\text{cuboid}} = 2(lw + lh + wh)

Six rectangular faces, in three matching pairs.

Acylinder=2πr2+2πrhA_{\text{cylinder}} = 2\pi r^2 + 2\pi r h

Two circular ends plus the curved side.

Acone=πr2+πrl,l=r2+h2A_{\text{cone}} = \pi r^2 + \pi r l,\quad l = \sqrt{r^2 + h^2}

The base plus the curved surface, using the slant height l.

Asphere=4πr2A_{\text{sphere}} = 4\pi r^2

Four times the area of a circle with the same radius.

Jinsi ya kutumia kikokotoo hiki

  1. Choose the shape and enter its measurements in the same unit.
  2. Press Calculate. Areas come out in that unit squared.

Mfano uliotatuliwa

A cylinder with radius 3 and height 5

The two circular ends: 2π × 3² = 18π.

The curved side: 2π × 3 × 5 = 30π.

Total surface area = 18π + 30π = 48π ≈ 150.796447.

Maswali yanayoulizwa mara kwa mara

What is the difference between surface area and volume?

Surface area is the area of the outside (how much paint covers it); volume is the space inside (how much it holds).

What is the slant height of a cone?

The distance from the tip down the side to the edge of the base: l = √(r² + h²).

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