Question

Identify the area of the rhombus. The answer with the red arrow is incorrect!

Answer 1

`\large\boxed{A=240\ cm^2}`

Explanation:

Look at the picture.

The formula of an area of a rhombus:

`A+(d_1d_2)/(2)`

d₁, d₂ - diagonals

We have d₁ = 30 cm.

Use the Pythagorean theorem to calculate d₂ = 2x.

`x^2+15^2=17^2`

`x^2+225=289` subtract 225 from both sides

`x^2=64\to x=√(64)\\\\x=8\ cm`

d₂ = (2)(8) = 16 cm.

Substitute:

`A=((30)(16))/(2)=(30)(8)=240`