SELVA SOFTWARE, INC.

CLAST TEST # 1 :

5. Given that AB | BC which of the following statements is true for the figure shown.

A) x = 90⁰ B) x =120⁰ C) x = 130⁰ D) x = 150⁰

Solution:

(1) If   AB |   BC ( | : perpendicular lines) then the ABC is a right angle (A right angle has a measure of 90⁰)
        ABC = 90⁰
(2) BAC + 120⁰= 180⁰(A straight angle has a measure of 180⁰)
      BAC = 180⁰ - 120⁰      BAC = 60⁰
(3) BCA + BAC + ABC = 180⁰   (The sum of the measures of the interior angles of a triangle is 180⁰)
       BCA + 60⁰ + 90⁰ = 180⁰ BCA = 180⁰- 60⁰ - 90⁰ BCA = 180⁰- 150⁰
BCA = 30^0

(4) x + BCA = 180⁰(A straight angle has a measure of 180⁰)
         x + 30⁰ = 180⁰ x = 180^{0 -} 30⁰ x = 150⁰

Answer: D) x = 150⁰