In △ABC , if a = 36 cm and  m∠C  = 23 ° , then what is the length of altitude h? Round your answer to the nearest whole number.  (1 point) Responses 14 cm 14 cm 39 cm 39 cm 92 cm 92 cm 33 cm

1 answer

To find the length of the altitude \( h \) from vertex \( C \) to side \( AB \) in triangle \( ABC \), we can use the following formula for the area \( A \) of the triangle:

\[ A = \frac{1}{2} \times b \times h \]

where \( b \) is the base of the triangle (the length of side \( AB \) in this case), and \( h \) is the altitude from vertex \( C \) to \( AB \).

We can also express the area of triangle \( ABC \) using side \( a \) and included angle \( C \):

\[ A = \frac{1}{2} \times a \times b \times \sin(C) \]

From the given information:

  • \( a = 36 \) cm (length of side opposite angle \( A \))
  • \( m∠C = 23^\circ \)

To find the altitude \( h \), we first need to determine the length of side \( b \) (which is the side opposite angle \( C \)). We can use the sine function to find this:

\[ \frac{a}{\sin(A)} = \frac{b}{\sin(B)} = \frac{c}{\sin(C)} \]

However, we need to express \( h \) in terms of \( a \) and \( C \).

The altitude can also be calculated directly using the formula:

\[ h = a \cdot \sin(C) \]

Now substituting the values:

\[ h = 36 \cdot \sin(23^\circ) \]

Using a calculator to find \( \sin(23^\circ) \):

\[ \sin(23^\circ) \approx 0.3907 \]

Now calculate \( h \):

\[ h \approx 36 \cdot 0.3907 \approx 14.0652 \]

Rounding this to the nearest whole number, we find:

\[ h \approx 14 \text{ cm} \]

So the length of the altitude \( h \) is approximately 14 cm.