3. 180 - (53+68) = 59
The answer is B. 59°
4.
Part A: The measure of a is 70°.
Explanation: The angle sum in any triangle is 180°. 70 + 40 is 110. To find the final angle, subtract 110 from 180. 180 - 110 = 70
Part B: The length of x is 5m.
Explanation. The triangle is an isosceles triangle. We know this because the two angles on the base are equal. Since this is an isosceles triangle, the two longer sides are the same length. Therefore: x = 5 m.