Question 43·Easy·Right Triangles and Trigonometry
A wheelchair ramp forms a right triangle with the ground. The ramp is 13 feet long, and the horizontal distance from the bottom of the ramp to the wall is 12 feet. Let be the angle the ramp makes with the ground.
What is the value of ?
For right-triangle trig questions, identify the hypotenuse first (the longest side, opposite the right angle). Then, relative to , decide which given side is adjacent. Apply .
Hints
Recall what cosine means
In a right triangle, .
Find the hypotenuse
The hypotenuse is the side opposite the right angle. In this situation, it is the ramp (the longest side).
Find the adjacent side
The adjacent side is the leg next to that is not the hypotenuse. Here, it is the horizontal distance along the ground.
Desmos Guide
Compute the cosine ratio
Enter the fraction into Desmos to get its decimal value.
Match to the choices
Choose the answer option that equals the fraction you entered, which is .
Step-by-step Explanation
Identify adjacent and hypotenuse
The ramp length (13 feet) is the hypotenuse. The horizontal distance along the ground (12 feet) is the side adjacent to .
Use the cosine ratio
By definition,
So, .