Here, sum of all the interior angles = ∠DEA + ∠EAB + ∠ABC + ∠BCD + ∠CDE

The figure in this is a pentagon with 5 number of sides.

FORMULA  FOR  FINDING  THE SUM  OF A  n-sided POLYGON -

( n-2 ) × 180°

Substituting the values.

Here, n = 5

∴ Sum of all the interior angles of a pentagon is -

( 5-2 ) × 180°

= 3 × 180 °

= 540°

Ans - ∠DEA + ∠EAB + ∠ABC + ∠BCD + ∠CDE = 540°