Chapter 7 Lecture A
Bring your calculator to this lecture!
Quiz 12
Quiz 13
Quiz 14
Homework 28
have your calculator handy for the homework!
Use your calculator to do your homework and quizzes.
Test problems will be only “famous” angles. Or you can leave your answer with an
inverse trig function!
1
Right triangle applications
Suppose theta is an acute angle.
Let’s discuss angle of elevation and angle of depression:
An eight foot ladder leans against a 15 foot wall. The angle of elevation of the ladder to
the ground is 60. How far up the wall is the ladder?
2
A wire 75 feet long is attached to the top of a telephone pole. The wire makes an angle
of elevation of 67° with the ground. How tall is the pole?
Popper 18, Question 01
3
Onnie is 5 feet tall. When looking at the top of a 120 foot building she makes an angle of
elevation of 45. How far is she from the building?
Mike, a 18” dog, is standing on his dog house – which is 2 feet tall. The angle of
elevation to a squirrel in the sycamore tree is 47° and the distance from his eye to the
squirrel is 40 feet. How far up the tree is the squirrel?
4
Given an isosceles right triangle with hypotenuse length 9 2 , what is the side length?
Given a triangle with angle C is a right angle and angle B is 30°, if the measure of the
base is 15cm, what are the measures of the other 2 sides?
5
Given an isosceles triangle with side length 3 and base length 8, what are the base angle
measures?
hint: in the homework and on the quiz, you’ll need a calculator.
On the test: famous angles or inverse function form is the way to do.
Popper 18, Question 2
6
Given a right triangle SQR with R the right angle, with the hypotenuse length 12 and
angle Q measures 28, what is the length of SR to one significant digit?
Popper 18, Question 3
7
Given a 3 – 4 – 5 triangle, what are the measures of the angles to one significant digit?
8
Given a right triangle SQR with R is the right angle and the measure of angle Q is 12
degrees and QR is 7 cm, what is the formula you’ll use to solve for the length of the
hypotenuse, x? What is the measure to one significant digit?
9
Popper 18, Question 4
10
Given a right triangle CUB with U being the right angle, the measure of CU is 8 and the
measure of UB is 15, what is the formula you’ll use to solve for the measure of angle B?
What is the measure to 1 significant digit?
11
Given right triangle KAM with angle M being the right angle, side KA, the hypotenuse,
measures 12 feet and AM, the base, measures 7 feet, what is the measure of angle K?
Homework heads up:
Given: Triangle BDC with angle C is 90 and angle D is 30, nested in triangle ABC with
the measure of angle A being 15 degrees. The length of AD is 200 feet. What is the
measure of BC?
12
Popper 18, Question 5
13
From a point on the ground, the angle of elevation to the top of a building is 45°. Moving
out 75 feet to another point on the ground, the angle of elevation is 30°. How high is the
building?
14
Popper 18, Question 6
Popper 18, Question 7
15
Popper 18, Question 8
16
Popper 18, Question 9
17
Popper 18, Question 10
18