measure of the other acute angle?


4. If two of the three angles in a triangle have measure 34º and
72º, what is the measure of the third angle?


5. Find the angle measures of a triangle if the second angle
measures 10 degrees less than twice the first, and the third
angle measures 25 degrees more than the second.


6. The measure of the second angle is 15 degrees more than the measure
of the first angle. The measure of the third angle is 45 degrees more than
the measure of the first angle. Find the measures of the interior angles in
the triangle.

Respuesta :

Step-by-step explanation:

step 1. the 3 internal angles of a triangle add up to 180°. let x be the 3rd angle

step 2. x + 34 + 72 = 180

step 3. x = 74°.

step 4. for problem 5 let the internal angles be a, b, and c

step 5. so b = 2a - 10, c = b + 25

step 6. we also know that a + b + c = 180

step 7. so a + (2a - 10) + (b + 25) = 180 by substitution

step 8. a + (2a - 10) + ((2a - 10) + 25) = 180 also by substitution

step 9. 3a - 10 + 2a + 15 = 180

step 10. 5a + 5 = 180

step 11. a = 35°

step 12. therefore b = 2a - 10 = 60°, c = 85°.