Use an equation that shows that the measures of the angles are equal.
x=10^(∘)
Practice makes perfect
Consider that ∠ 1 and ∠ 3 in the given diagram are the same measure.
We want to find the value of x. From the given diagram, we know that the measure of ∠ 1 is given by the expression (9x)^(∘) and the measure of the ∠ 3 is 90^(∘).
(9x)^(∘) = 90deg
Let's solve this equation for x. Note that to make calculations easier, we can ignore the symbol ^(∘) and add it to the result.
