How to open the triangular key door in MADiSON

gamepur.com:

When you first start MADiSON, you are tasked with getting out of a small room. Once that is done, you will find yourself in a thin hallway leading to the other parts of the house. While the hallway is quite bland, a peculiar door stands out at the end near where you entered. This door has two locks that both have triangles on them. Not the typical type of lock that you see in an everyday house, but a necessary one to open if you want to complete the story.

There are two keys that you need to track down to open the door. The first of these keys can be found pretty early on in the game. Before you can get the first key, you need to make your way to grandpa’s house through the study.

Once you get into grandpa’s house, head for the kitchen. You should already be near it if you just entered the house. You can find the first of the keys in the bottom corner cabinet like in the image above.

Related: How to solve the attic portrait puzzle in MADiSON

The second key won’t be able to be obtained for quite some time. Before you can get your hands on it, you will need to complete the attic portion of the game and the cathedral portion. After completing both parts of the game, you can head to the basement to grab the crowbar. Use the crowbar to get the wedding ring from under the floorboard in grandpa’s bedroom closet.

Continue through the game to the small room where you originally got the instant camera from. At this point in the game, you should see four Virgin Mary statues in the room surrounding the chair. The second triangle key is on the chair where you picked up the camera. With both keys in your possession, you can go open the door that you have been waiting to open.