10th Class Mathematics Introduction to Trigonometry Question Bank Case Based (MCQs) - Introduction to Trigonometry

Direction: Q. 26 to 30

In structural design a structure is composed of triangles that are interconnecting. A truss is one of the major types of enginnering structures and is especially used in the design of bridges and buildings. Trusses are designed to support loads, such as the weight of people. A truss is exclusively made of long, straight members connected by joints at the end of each member.

This is a single repeating triangle in a truss system.

Based on the above information give the, answer of the following questions:

In above triangle, what is the Length of AC?

A) \[5\,ft\]

B) \[6\,ft\]

C) \[8\,ft\]

D) \[\frac{8}{\sqrt{3}}\,ft\]

Correct Answer: C

Solution :

In right \[\Delta ABC,\]

\[\sin 30{}^\circ =\frac{AB}{AC}\,\,\,\,\,\Rightarrow \,\,\,\,\,\,\,\,\frac{1}{2}=\frac{4}{AC}\]

\[\Rightarrow \,\,\,\,\,\,\,\,\,\,A\] \[C=8ft\]

So, option [c] is correct.