5. If AABC = ADEF, find the measure of

Can someone explain me?

Option A) angle B = 67°

Step-by-step explanation:

I'll use " [ " symbol for saying angle.

Alright so ...

since triangle ABC and triangle DEF are congruent

it means [ A = [ D

[ B = [ E

[ C = [ F

here [ A = 78° (which means [ D is also 78°)

and ..[ F = 35° (which means [ C is also 35°)

-->So now all you need to know to find [ B is to know the other two angles in the triangle. and thats where ..

you write.. [ A + [ B + [ C = 180° (angle sum property)

78° + [ B + 35° = 180°

113° + [ B = 180°

[ B = 180 - 113

= 67°

I hope that clears the concept , if you have any questions regarding it I'd love to help .

the answer is c hope it

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.