780

56°

(100°

(x + 48) °

The Question is Incomplete still What i understood I let you Explain.

x = 78°

Step-by-step explanation:

Let

m∠ A = 78°

m∠ B = 56°

m∠ C = 100°

m∠ D = (x + 48) °

Be angles of Quadrilateral.

To Find:

x = ?

Solution:

Property of a Quadrilateral sum of the measures of the angle is 360°.

∴ m∠ A + m∠ B + m∠ C + m∠ D = 360°

Substituting above given values we get

∴ 78° + 56° + 100° + (x + 48°) = 360°

∴ x + 282° = 360°

∴ x = 360° - 282°

∴ x = 78° ... which the required answer