Answer:
90 degrees
Step-by-step explanation:
A circle circumscribed over a right triangle is the same as a circle circumscribed over a rectangle built from the extension of the right triangle.
That tells us that the hypotenuse is the diameter of the circle in that case.
Here, we can see a triangle that has the hypotenuse as the diameter of the circumscribed circle. We can infer that the triangle is a right triangle.
9514 1404 393
Answer:
Step-by-step explanation:
The marked angles form a linear pair, so have a sum of 180°.
(4a +10) +(6a) = 180
10a = 170 . . . . . . . . . . subtract 10
a = 17 . . . . . . . . . . . . . divide by 10
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Then the measure of angle ABC is ...
∠ABC = 4a +10 = 4(17) +10 = 68 +10 . . . . . substitute 17 for 'a'
∠ABC = 78°
The answer is A. I plugged it into a TI-83 calculator. If you need to know how I did that I will be happy to help