Answer
$$A=30°$$
$$B=60°$$
Work Step by Step
Find angle A.
We can use the trigonometric function for sine to find angle A.
$sin A=\frac{a}{c}$
$sin A=\frac{72cm}{144cm}$
$sin A=0.5$
Now we solve for A by multiplying both sides of the equation by the inverse sine.
So,
$sin^{-1}(sin A) = sin^{-1}(0.5)$
$A = sin^{-1}(0.5)$
$A=30°$
Find angle B.
We know that in right triangles the sum of the acute angles is 90°.
So, $A+B=90°$
Solving for $B$, we get
$B=90°-A$
$B=90°-30°$
$B=60°$
