Triangle ABC is an isosceles right triangle. What is the measure of one base angle? 30º 45º 60º 90º pl help

45

Step-by-step explanation:

In an isosceles triangle the base angles are the same. If all of the angles in a triangle add up to 180 and one of them is 90 because it’s a right triangle, then both base angles add up to 90. 90/2 is 45, so that’s your answer.

45°

Step-by-step explanation:

The measure of a base angle of an isosceles right triangle is 45 degrees. In any triangle, the measure of all three angles equals 180 degrees

In rt angle triangle,

One angle is 90 deg.

other 2 angles are equal (Angles Opp. to equal sides)

90°+45°+45°=180° (Angle sum property of triangle)

so other 2 angles are 45° each. (Base angles)

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your answer is

a.

5

step-by-step explanation: