A. 37
b. 62
c. 60
d. 39

Angle ABC = 81°

Angle BAC = a°

Angle BCA = 62°

The measure of a.

We know that,

➪ ∠ ABC + ∠ BAC + ∠ BCA = 180°

➪ 81° + a° + 62° = 180°

➪ a° + 143° = 180°

➪ a° = 180° - 143°

➪ a° = 37°

Therefore, the measure of a is 37°.

Now, the three angles of the triangle are 81°, 37° and 62°.

∠ ABC + ∠ BAC + ∠ BCA = 180°

✒ 81° + 37° + 62° = 180°

✒ 180° = 180°

✒ L. H. S. = R. H. S.

( Note: Kindly refer to the attached file. )

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step-by-step explanation: