Question

The ceiling of Stacy's living room is a square that is 25 ft long on each side. Stacy

knows the diagonal of the ceiling from corner to corner must be longer than 25 ft,
but she doesn't know how long it is.
Solve for the length of the diagonal of Stacy's ceiling in two ways:
(a) Using the Pythagorean Theorem.
(b) Using trigonometry.
Round each answer to the nearest whole number and make sure to show all your
work. (Hint: the answers should be the same!)
Please help !!!

Answer 1

A. 35 ft.

B. 35 ft

Explanation:

Please see attached photo for diagram.

A. Determination of the diagonal using pythagorean theorem.

A square has all sides equal. Thus, the diagonal of the square can be obtained as follow:

Ist leg (L₁) = 25 ft

2nd leg (L₂) = 25 ft

Diagonal (d) =?

d² = L₁² + L₂²

d² = 25² + 25²

d² = 625 + 625

d² = 1250

Take the square root of both side

d = √1250

d = 35 ft

B. Determination of the diagonal using trigonometry.

Since all the sides in a square are equal, the angle between each leg will be 90°. Thus, the diagonal will bisect the angle between the two leg equally i.e

Angle between Diagonal and each leg = 90/2 = 45°

Finally, we shall determine the length of the diagonal. This can be obtained as follow:

Angle θ = 45°

Opposite = 25 ft

Hypothenus = d

Sine θ = Opposite / Hypothenus

Sine 45 = 25 / d

0.7071 = 25 / d

Cross multiply

0.7071 × d = 25

Divide both side by 0.7071

d = 25 / 0.7071

d = 35 ft