Answer:
x =

Step-by-step explanation:
The sum of the interior angles of a quadrilateral is
, so that from the given question:
<A + <B + <C + <D =

(2x + 35) + (3x - 5) + (x + 10) + (4x + 20) =

10x + 60 =

10x =
- 60
= 300
x =

= 30
x =

So that,
<A = (2x + 35) = (2*30 + 35) =

<B = (3x - 5) = (3*30 - 5) =

<C = (x + 10) = (30 + 10) =

<D = (4x + 20) = (4*30 + 20) =

Thus,
+
+
+
=
