In each of the given pairs of triangles, find which pair of triangles are similar. State the similarity criterion and write the similarity relation in symbolic form.

Question

Philoid · Accepted Answer

In ∆ABC, we can find ∠ABC.

∠ABC + ∠BCA + ∠CAB = 180° [∵ sum of all the angles of a triangle is 180°]

⇒ ∠ABC + 70° + 80° = 180°

⇒ ∠ABC + 150° = 180°

⇒ ∠ABC = 180° - 150°

⇒ ∠ABC = 30°

We can observe from triangles ABC & MNR,

∠ABC = ∠MNR

∠CAB = ∠RMN

Hence, by AA similarity we can say, ∆ABC ∼ ∆MNR