面積の計算機

図形を選び、寸法を入力して「計算」を押してください。

結果

値を入力して「計算」を押すと結果が表示されます。

公式

Atriangle=12bhA_{\text{triangle}} = \tfrac{1}{2} b h

A triangle is half of a parallelogram with the same base and height.

Atrapezoid=12(a+b)hA_{\text{trapezoid}} = \tfrac{1}{2}(a + b) h

Average the two parallel sides, then multiply by the height.

この計算ツールの使い方

  1. Choose the shape; the inputs change to match it.
  2. Use the perpendicular height, not a slanted side.

解き方付き例題

Triangle with base 10 and height 6

A = ½ × 10 × 6 = 30 square units.

よくある質問

What units is the answer in?

Square units of whatever you entered — e.g. cm in gives cm².

Where is the circle?

Use the Circle Calculator, which also gives exact answers in terms of π.

詳しく学ぶ