Which sign makes this number sentence true? 780 ÷ 2 [ ] 390

The sign that makes the sentence true is an equal sign, =.

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180

answer: the answer is 40.82

step-by-step explanation: 3.14 x 13(or half of 26) to the power of 2