Question

For each triangle, check all that apply. Triangle A 9 Scalene Isosceles O Equilateral 9 Triangle B 30° O Scalene O Isosceles O Equilateral 60° 60° Triangle C 60 Scalene O Isosceles O Equilateral d 60° Triangle D 10 O Scalene O Isosceles O Equilateral

Answer 1

Tiangle A.

In this triangle we can observe, all of its sides measure 9, so this triangle has 3 equal sides.

This is the definition of equilateral triangle.

Triangle B.

In this triangle we have a right angle 90°, a 30° angle and a 60° angle.

We need to apply the angle-side relationships. The side opposite to the largest angle, will be the longest side, and the opposite side to the smallest angle, will be the shortest side.

As we have 3 angles with different measures, then the opposite sides will have different lengths too. So, thi is a scalene triangle.

Triangle C.

The 3 given angles measure the same 60°, as we said before, the measure of the opposite side to the angles has a relationship with the measure of the angle. As they measure the same, then the 3 sides will have the same measure too. This is an equilateral triangle.

Triangle D.

In this triangle, we can observe it has 2 sides that measure 6 units, and 1 side that measure 10 units. So, it has 2 sides of the same length, this it the definition of isosceles triangle.