Question

$\angle$a and $\angle$b are complementary to each other. $\angle$a = $8x^\circ$ $\angle$b = $10^\circ$ find the value of x. a 8 b 10 c 40 d 80

Explanation:

Step1: Recall complementary angles rule

Complementary angles sum to \(90^\circ\), so \(\angle A + \angle B = 90^\circ\).

Step2: Substitute given values

Substitute \(\angle A = 8x^\circ\) and \(\angle B = 10^\circ\) into the equation: \(8x + 10 = 90\).

Step3: Solve for \(x\)

Subtract 10 from both sides: \(8x = 90 - 10 = 80\). Then divide by 8: \(x = \frac{80}{8} = 10\). Wait, no—wait, 90 - 10 is 80? Wait, no, 90 - 10 is 80? Wait, 8x +10 =90 → 8x=80 → x=10? Wait, but let's check again. Wait, complementary angles add to 90, so 8x +10 =90. Subtract 10: 8x=80. Divide by 8: x=10. Wait, but option B is 10? Wait, but let's re - check. Wait, 8x +10 =90. 8x=80. x=10. So the value of x is 10.

Answer:

B. 10