angles 1 and 2 are complementary and congruent. what is the measure of angle 1?\n30°\n45°\n50°\n75°

Answer:

B. $45^{\circ}$

Explanation:

Step1: Recall complementary - angle definition

Complementary angles sum to $90^{\circ}$, so $\angle1+\angle2 = 90^{\circ}$.

Step2: Use congruent - angle property

Since $\angle1$ and $\angle2$ are congruent, $\angle1=\angle2$. Let $\angle1 = x$ and $\angle2=x$. Then $x + x=90^{\circ}$.

Step3: Solve the equation

Combining like - terms gives $2x = 90^{\circ}$. Dividing both sides by 2, we get $x=\frac{90^{\circ}}{2}=45^{\circ}$. So the measure of $\angle1$ is $45^{\circ}$.