Answer:
<B = 32°
c = 9.43
Explanation:
To find the measure of <B, add up the measures of the two angles that you know and subtract from 180°.
58° + 90° = 148°
180° - 148° = 32°
The measure of <B is 32°.
To find the length of side c, use the Pythagorean Theorem.
a² + b² = c²
5² + 8² = c²
25 + 64 = c²
89 = c²
c = √89
c = 9.433981132 ⇒ 9.43 (rounded to two decimal places)
The length of side c = 9.43.
Hope that helps.