SOLUTION: To determine the distance across a lake, a surveyor selected two points P and Q, one on each shore and directly opposite each other. On the shore containing P, another point R was

Algebra.Com
Question 1171560: To determine the distance across a lake, a surveyor selected two points P and Q, one on each shore and directly
opposite each other. On the shore containing P, another point R was chosen, 50 ft from P, so that the line segment PR
was perpendicular to the line segment PQ. The angle having the sides PR and PQ was measured to be 78.24°. What
is the distance across the lake? Round off your answer to two decimal places.

Answer by math_tutor2020(3817)   (Show Source): You can put this solution on YOUR website!

Diagram

The surveyor is on the side labeled "shore 1". Point Q could be any landmark on the opposite shore such as a rock or tree.

I think your teacher made a typo and should have said "The angle having the sides PR and QR was measured to be 78.24°". The angle having sides PR and PQ is the 90 degree angle.

Based on the diagram above, we know that,
tan(angle) = opposite/adjacent
tan(angle R) = PQ/PR
tan(78.24) = x/50
50*tan(78.24) = x
x = 50*tan(78.24)
x = 240.174013162624
x = 240.17
Make sure your calculator is in degree mode.

Answer: The distance across the lake is approximately 240.17 feet

RELATED QUESTIONS

Two surveyors are on the opposite sides of a swamp. To find the distance between them,... (answered by psbhowmick)
A boy standing on the shore of a lake 1 mile wide wants to go to the store 3 miles down... (answered by richwmiller,Alan3354)
To determine the distance between two points on opposite sides of a pond, a surveyor... (answered by Theo)
A surveyor is measuring the distance across a small lake. He has set up his transit on... (answered by Theo)
a surveyor wishes to find the distance between two in accessible points A & B on opposite (answered by jsmallt9)
Jamal sees a tree on the shore directly across a lake and wonders what the distance is... (answered by stanbon)
a surveyor wishes to find the distance between two inaccessible points A&B on opposite... (answered by jsmallt9)
There is a small island in the middle of a 100m wide river and a tall tree stands on... (answered by Theo)
A small island in the middle of river which 100 m wide has a tall tree standing on it P... (answered by ikleyn)