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Solve the right triangle.(Hint: Find all missing sides and angles)

Solve the right triangle.(Hint: Find all missing sides and angles)-example-1
User Jkoelker
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1 Answer

19 votes
19 votes

Answer:

• BC = 7√5 units.

,

• m∠B=41.8°

,

• m∠C=48.2°

Explanation:

First, find the length of the third side, BC using the Pythagorean theorem.


\begin{gathered} AB^2=AC^2+BC^2 \\ 21^2=14^2+BC^2 \\ BC^2=21^2-14^2 \\ BC=√(21^2-14^2) \\ BC=√(245) \\ BC=√(49*5) \\ BC=7√(5) \end{gathered}

The length of the third side, BC is 7√5 units.

(b)Next, find the measure of angle B.

• The side length ,opposite, B = 14

,

• The length of the ,hypotenuse, = 21

From trigonometric ratios:


\begin{gathered} \sin B=(Opposite)/(Hypotenuse) \\ \sin B=(14)/(21) \\ T\text{ake the arcsine of both sides:} \\ B=\arcsin((14)/(21)) \\ B\approx41.8\degree \end{gathered}

The measure of angle B is 41.8 degrees.

(c)Finally, find the measure of angle C.

In a right triangle, the sum of the two acute angles is 90 degrees, therefore:


\begin{gathered} m\angle B+m\angle C=90\degree \\ 41.8\operatorname{\degree}+m\operatorname{\angle}C=90\operatorname{\degree} \\ m\operatorname{\angle}C=90\operatorname{\degree}-41.8\operatorname{\degree} \\ m\operatorname{\angle}C=48.2\operatorname{\degree} \end{gathered}

The measure of angle C is 48.2 degrees.

User Makson
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