Di*he"dral (?), *a.* **1.**
Of a kite or an aëroplane, having wings that make with one
another a dihedral angle, esp. when the angle between the upper sides
is less than 180°.

**2.** *(Aëronautics)* Of wing pairs,
inclined at an upward angle to each other.

Di*he"dral (?), *a.* [Gr. di-
= di`s- twice + &?; a seat, bottom, base, fr. &?; to sit.
Cf. __Diedral__.] Having two plane faces; as, the
*dihedral* summit of a crystal.

**Dihedral angle**,

the angular space contained
between planes which intersect. It is measured by the angle made by
any two lines at right angles to the two planes.Di*he"dral (?), *a.* **1.**
Of a kite or an aëroplane, having wings that make with one
another a dihedral angle, esp. when the angle between the upper sides
is less than 180°.

**2.** *(Aëronautics)* Of wing pairs,
inclined at an upward angle to each other.