Screen Size

Computer screens and television screens are usually measured by the diagonal of
the screen. For example, a screen of size 60 inches would have a diagonal of 60
inches, a width of 52 inches, and a height of 30 inches.
Yoselin would like to install a new screen on a shelf that is 17 inches tall and 50
inches wide. She would like the screen to be the largest size that will fit on the
shelf. She knows the diagonal and width of the 4 screens listed below.

Screen Diagonal Width Height
A 15” 13”
B 22” 19”
C 32” 28”
D 40” 35”

1. Use the Pythagorean Theorem to calculate the height of each screen, and
complete the table.

1 answer

To calculate the height of each screen using the Pythagorean Theorem, we can use the formula:

\[ c^2 = a^2 + b^2 \]

where:

  • \( c \) is the diagonal of the screen,
  • \( a \) is the width of the screen,
  • \( b \) is the height of the screen.

Rearranging the formula to find the height \( b \):

\[ b = \sqrt{c^2 - a^2} \]

Now, let's calculate the height for each screen:

Screen A

  • Diagonal \( c = 15 \) inches
  • Width \( a = 13 \) inches

\[ b = \sqrt{15^2 - 13^2} = \sqrt{225 - 169} = \sqrt{56} \approx 7.48 \text{ inches} \]

Screen B

  • Diagonal \( c = 22 \) inches
  • Width \( a = 19 \) inches

\[ b = \sqrt{22^2 - 19^2} = \sqrt{484 - 361} = \sqrt{123} \approx 11.09 \text{ inches} \]

Screen C

  • Diagonal \( c = 32 \) inches
  • Width \( a = 28 \) inches

\[ b = \sqrt{32^2 - 28^2} = \sqrt{1024 - 784} = \sqrt{240} \approx 15.49 \text{ inches} \]

Screen D

  • Diagonal \( c = 40 \) inches
  • Width \( a = 35 \) inches

\[ b = \sqrt{40^2 - 35^2} = \sqrt{1600 - 1225} = \sqrt{375} \approx 19.36 \text{ inches} \]

Now, let's complete the table with the calculated heights:

| Screen | Diagonal | Width | Height | |--------|----------|-------|-----------| | A | 15” | 13” | 7.48” | | B | 22” | 19” | 11.09” | | C | 32” | 28” | 15.49” | | D | 40” | 35” | 19.36” |

Yoselin can use this information to choose the largest screen that will fit on her shelf with dimensions 17 inches tall and 50 inches wide. Based on the calculated heights, screens A, B, C, and just barely screen D can fit; however, the largest size that fits height-wise is screen D with a height of approximately 19.36 inches, which is too large for the 17-inch height maximum. So she would need to choose Screen C, which has a height of approximately 15.49 inches.