Question

In square ABCD, m∠BCE=(5x+9)∘.

What is the value of x?

Enter your answer, as a decimal, in the box.

x =

Answer 1

x = 7.2

Explanation:

You want the value of x that makes ∠BCE = 45° = (5x +9)°.

Solution

Divide by ° and subtract 9 to get ...

36 = 5x

Divide by 5, and you have the value of x:

7.2 = x

The value of x is 7.2.

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Additional comment

You know that the corner angles of a square are 90°, and that the diagonals bisect the corner angles. Each half is 45°.