The area of a triangle is 64 cm^2. Given AB=11 cm and BC=15 cm find angle ABC.

1 Answer

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giorgiana1976 | College Teacher | (Level 3) Valedictorian

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To determine the measure of the angle B, we'll have to use the following formula that gives the area of triangle:

A = leg1*leg2*sine of the angle included/2

Since the lengths of AB and BC and the value of the area of triangle are known, we'll replace them within the formula above:

64 = 11*15*sin B/2

We'll multiply both sides by 2:

128 = 165*sin B

sin B = 128/165

sin B = 0.775

B = 50.80 degrees

The included angle ABC measures 50.80 degrees.