Answer: ∠A < ∠B < ∠C
Step-by-step explanation:
Given: In Δ ABC
AB = 18, BC = 10, and CA = 13
We can see that
10<13<18
Thus, BC < CA < AB ........................(1)
We know that in triangles the larger angle to opposite to the largest side if larger.
Since, ∠A is opposite to BC
∠B is opposite to CA
∠C is opposite to AB
Therefore, from (1), we have
∠A < ∠B < ∠C
Thus, the angles of ΔABC in order from smallest to largest will be
∠A < ∠B < ∠C
