Answer:
60⁰
Explanation:
A triangle has three angles.
The sum of its angles = 180⁰
[ By angle sum property ]
Let the unknown angle be 'x'
Then,
30⁰ + 90⁰ + x = 180⁰
120⁰ + x = 180⁰
x = 180⁰ - 120⁰
x = 60⁰
Therefore, the unknown angle will be equal to 60⁰