In the given problem, the sum of two angles of a triangle is equal to its third angle.
We need to find the measure of the third angle.
Thus, it is given, in ΔABC
A+B+C ........(1)
Now, according to the angle sum property of the triangle, we get,
∠A +∠B + ∠C = 180°
∠C + ∠C = 180° (Using 1)
2∠C = 180°
`∠C = (180°)/2`
∠C = 90°
Therefore, the measure of the third angle is
∠C = 90°.