Sagot :
Answer:
flat geometric figure that has three sides and three angles. 2 : something that has three sides and three angles a triangle of land. 3 : a musical instrument made of a steel rod bent in the shape of a triangle with one open angle.
Step-by-step explanation:
triangle's interior angles always add up to 180 degrees. Therefore, 180=5x+7x+8x=20x -> 9=x So the three angles are 45, 63 and 72 degrees.