Answer:
Problem 3: 51°
Problem 5: 5 feet
Explanation:
Image 1:
We are asked to find the missing angle. First off, we know that the full semi-circle equals 180 degrees. knowing this, subtract the second angle from 180 to get the smaller angle.
180 - 129 = 51
The unkown angle is 51 degrees.
Image 2:
We are asked to find the missing side. Apply the numbers of the known sides to the Pythagorean Theorem.
a² + b² = c²
a² + 12² = 13²
a² + 144 = 169
a² = 25
a = 5
The missing side is 5 feet.