Question

The sum of interior angles of a triangle are: 78°,39° and a°. Find the value of a° a. 117° b. 102° c. 93° d. 63° e. Other:

Answer 1

Answer:

d. 63

Step-by-step explanation:

sum of 3 interior angles= 180°

78°+39°+a=180°

a= 180°- 117°

a= 63°

Answer 2

Answer:

D. 63°

Step-by-step explanation:

The Triangle Sum Theorem says that all of the angles in a triangle add up to 180°.

78° + 39° = 117°. Think of it like algebra. 180° - 117° = 63°. I hope this helps :)