Question

Triangle ABC has AB = AC, BC = 10 cm
and BAC = 90°. Calculate the lengths
of sides AB and AC to the nearest
millimetre.​

Answer 1

For any triangle, The sum of all three angles is 180 degree. In this example, A = 90 degree and B = 30 degree. So, C= 180 - 90 -30 = 60 degree.

AB is the opposite side for the angle C and AC is the opposite side for the angle B.

Sin 30 = AC / BC as BC is the opposite for the angle 90 degree and it is hypotenuse.

AC => BC * sin 30 => 8 * 1/2 = 4 CM

Sin 60 = AB / BC as BC is the opposite for the angle 90 degree and it is hypotenuse.

AB => BC * sin 60 => 8 * 1.732 / 2 => 6.928 CM

Answer 2

For any triangle, The sum of all three angles is 180 degree. In this example, A = 90 degree and B = 30 degree. So, C= 180 - 90 -30 = 60 degree.

AB is the opposite side for the angle C and AC is the opposite side for the angle B.

Sin 30 = AC / BC as BC is the opposite for the angle 90 degree and it is hypotenuse.

AC => BC * sin 30 => 8 * 1/2 = 4 CM

Sin 60 = AB / BC as BC is the opposite for the angle 90 degree and it is hypotenuse.

AB => BC * sin 60 => 8 * 1.732 / 2 => 6.928 CM