Answer:
m∠J = 45° , m∠I = 45° and m∠M = 90°
And the ΔJIM is an isosceles right angled triangle.
Explanation:
(a). In ΔJIM,
∠J = 2x + 15,
∠I = 5x - 30, and
∠M = 6x
Now, using angle sum property of a triangle that sum of all the angles in a triangle is 180°
⇒ ∠J + ∠I + ∠M = 180°
⇒ 2x + 15 + 5x - 30 + 6x = 180°
⇒ 13x -15 = 180°
⇒ 13x = 195
⇒ x = 15
Therefore, m∠J = 45° , ∠I = 45° and m ∠M = 90°
(b). Now, ΔJIM is a right angled triangle right angled at M.
Also, ∠J = ∠I = 45°
So, JM = IM ( because in a triangle sides opposite to equal angles are equal)
So, ΔJIM is an isosceles triangle because its two sides are equal.
Hence, ΔJIM is a right angled isosceles triangle right angled at M.