complementary angles

plural plural-only

(geometry) A pair of angles that sum to a right angle.

Japanese Meaning

（幾何学）二つの角の大きさの和が直角（90度）となる角の組み合わせ。

The complementary angles at the intersection of the two lines measured 30° and 60°.

2本の直線の交点にある、和が直角になる2つの角は30度と60度だった。

Sense（1）

(geometry) A pair of angles that sum to a right angle.

A = 30° and A′ = 60°, so A and A′ are complementary angles.