Year 10
Higher
Use trigonometry to find the perpendicular height of a triangle
Year 10
Higher
Use trigonometry to find the perpendicular height of a triangle
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Lesson details
Key learning points
- In this lesson, we will identify the perpendicular height of triangles, use trigonometry to find the perpendicular height and apply this to find the area of a triangle.
Licence
This content is made available by Oak National Academy Limited and its partners and licensed under Oak’s terms & conditions (Collection 1), except where otherwise stated.
3 Questions
Q1.
A ladder leans against a wall. It is 3m away from the wall at an angle of 60 degrees. What is the length of the ladder?
![An image in a quiz](/_next/image?url=https%3A%2F%2Foaknationalacademy-res.cloudinary.com%2Fimage%2Fupload%2Fv1707205687%2Fvk47tltof1pjqzmpctxi.png&w=640&q=75)
x = 1.5 m
x = 4.70 m
Q2.
2. A man stands exactly 8m from a lamppost. He looks to the top of the lamppost, as shown. What is the height of the lamppost? Answer to 1 dp
![An image in a quiz](/_next/image?url=https%3A%2F%2Foaknationalacademy-res.cloudinary.com%2Fimage%2Fupload%2Fv1707205689%2Fdiwe0fyjbesh2s3wowsd.png&w=640&q=75)
11.9 m
13.4 m
5.4 m
Q3.
Find the perpendicular height of this parallelogram ( to 1 dp)
![An image in a quiz](/_next/image?url=https%3A%2F%2Foaknationalacademy-res.cloudinary.com%2Fimage%2Fupload%2Fv1707172994%2Fbrbbbnljd13jlb6pftrt.png&w=1920&q=75)
10 cm
3.5 cm
3.54 cm
3 Questions
Q1.
If b is the base, identify the perpendicular height of this triangle.
![An image in a quiz](/_next/image?url=https%3A%2F%2Foaknationalacademy-res.cloudinary.com%2Fimage%2Fupload%2Fv1707167035%2Fse2m7fmqsk9anyspjgl1.png&w=640&q=75)
s
u
Q2.
Find the perpendicular height of the triangle.
![An image in a quiz](/_next/image?url=https%3A%2F%2Foaknationalacademy-res.cloudinary.com%2Fimage%2Fupload%2Fv1707167037%2Fovseftoezvefislkr44w.png&w=1080&q=75)
0.0333… cm
1 cm
Q3.
Find the perpendicular height of the triangle. Give your answer to one decimal place.
![An image in a quiz](/_next/image?url=https%3A%2F%2Foaknationalacademy-res.cloudinary.com%2Fimage%2Fupload%2Fv1707167044%2Ffkvoxvlamqk9utw09ljv.png&w=640&q=75)
5.9 cm
8 cm