Can someone please help me?

Question

In the right triangle RST, m∠S = 78º and the right angle is at vertex R. Find the measure of m∠T.

Answer 1

Answer: m∠T = 12^o

Explanation: The internal angles of any triangle will always add up to 180^o. Assume that the variable n is equal to the unknown angle m∠T. We know that angle m∠S is equal to 78^o and angle m∠R is equal to 90^o, and knowing the internal angles of a triangle add up to 180^o, we can express the problem as n + 78 + 90 = 180.

Isolating n by subtracting 78 and 90 from both sides leaves us with n = 12^o or m∠T = 12^o

Answer 2

m∠T = 180° - 90° - 78°