Mathematics

Problem

In parallelogram

LMNO

, two consecutive interior angles are

\angle L = (3a + 10)^\circ

and

\angle M = (5a - 2)^\circ

. (a) Find the value of

a

. (b) Determine the measure of all four interior angles of

LMNO

. (c) State whether the parallelogram is acute-angled or obtuse-angled, giving a brief reason.