Answer:
a. x = 24
b. x = 40
Explanation:
a.
You are given a right triangle, so use the Pythagorean theorem
a^2 + b^2 = c^2
x^2 + 18^2 = 30^2
x^2 + 324 = 900
x^2 = 576
x = 24
b.
The sum of the measures of all angles is 360 degrees.
x + 2x + 2x + 20 + 3x + 20 = 360
8x + 40 = 360
8x = 320
x = 40