Question

Which could be the measures of the three angles of an acute triangle.A. 40, 90, 50B. 45, 45, 90C. 25, 25, 130D. 70, 80, 30

Answer 1

Option D

Explanation:

Remember that the sum of all angles in ANY triangle is 180 degrees. Also, remember that an acute triangle has angles that are all less than 90 degrees. So not only do our options have to add up to 180 degrees, but they also have to be less than 90 degrees in order for the triangle to be acute.

We can immediately exclude options A, B, and C because all three options have angles greater than 90 degrees, which means the triangle isn't acute.

Your answer is option D or "70, 80, 30." Since...

70 + 80 + 30 = 180
70 < 90
80 < 90
30 < 90

Hope this helps.