Ok so for number 1 when you see it with three different set of lines it is scalene. When you see one like number two with two of the same set of lines it is isosceles. When you see one with all three of the same set of lines it is equilateral. So the answers would be 1.d, 2.b, 3.b, 4.a
A way to remember this is for isosceles think of it as eyes you have two eyes that are alike. For equilateral all parts are equal. Scalene as a scale(the numbers can be all over the place am I right) for a right triangle it has to have one corner at a 90 degree angle so it makes a square.
Brainliest?