Triangle Eyes

In manga and anime, sometimes when a character is angry, scowling, they're drawn with semi-circle eyes, or "triangle eyes," sankaku-me 三角目, typically as completely white eyes, regardless of what their original shape was.^{(tonbi.jp:三角目)}

Character: Kurahashi Riko 倉橋莉子
Anime: Love Lab, Ren'ai Rabo 恋愛ラボ (Episode 1)

• Examples
  • With Attacks
• Eye in Triangle
• References

Examples

For reference, some examples:

Character: Edward Elric エドワード・エルリック
Anime: Fullmetal Alchemist: Brotherhood, Hagane no Renkinjutsushi 鋼の錬金術師 (Episode 1)

• A forehead shadow, popped veins, anger marks, jagged teeth, and steam coming out of nose are other angry symbols.

Character: Kokkuri-san コックリさん
Anime: Gugure! Kokkuri-san 繰繰れ！コックリさん (Episode 1)

Left: Hiiragi Tsukasa 柊つかさ
Middle: Hiiragi Kagami 柊かがみ
Right: Izumi Konata 泉こなた
Anime: Lucky☆Star, らき☆すた (Episode 7)

Character: Shigure シグレ
Anime: Hataage! Kemono Michi 旗揚!！けものみち (Episode 4)

With Attacks

Triangle eyes are also used when a character is furiously attacking another, specially in comedic manner.

Left: Misumi Makoto 深澄真
Right: Tomoe 巴
Anime: Tsuki ga Michibiku Isekai Douchuu 月が導く異世界道中 (Episode 3)

• Context: an angry Makoto hits Tomoe with a rolled up book for saying something silly.
• See tsukkomi ツッコミ for details on comedic violence.
• See rumic sign for the gesture Tomoe is doing with her hands as she flies away.

Top: Aizawa Eiko 相沢栄子
Bottom: Ika Musume イカ娘
Anime: Shinryaku! Ika Musume 侵略！イカ娘 (Episode 1)

• Context: an angry Eiko gives Ika-musume a noogie for breaking the wall.

Attacker: Hidaka Azumi 日高安純
Receiver: Minami Kaede 南楓
Anime: Wagamama Fairy Mirumo de Pon! Golden, わがまま☆フェアリー ミルモでポン！ ごおるでん (Episode 4)

• Context: an angry Azumi puts Kaede in a cobra twist wrestling hold.

Attacker: Moegi Emo 萌黄えも
Receiver: Moegi Shunta 萌黄春太
Anime: Kiratto Pri☆chan, キラッとプリ☆チャン (Episode 16)

• Context: Emo puts her younger brother, Shunta, in her original Emo special えもスペシャル wrestling hold.

Attacker: Mamiya Ayumi 魔宮あゆみ
Anime: Magikano, マジカノ (Episode 7)

• Context: an angry Ayumi uses a denki-anma 電気あんま on some poor fella.

Eye in Triangle

An eye in a triangle or pyramid is called the eye of providence or all-seeing eye of God.

Left: the "Eye of Providence," Purobindensu no Me プロビデンスの目
Right: Honda Hanako 本田華子
Anime: Asobi Asobase あそびあそばせ (Episode 8)

• Context: Hanako worries about God's wrath against virgins.

Character: Bill Cipher, ビル・サイファー
Anime: Gravity Falls (Episode 19)

• Context: Bill Cipher's design is based on the Eye of Providence.

References

• 三角目 - tonbi.jp, accessed 2020-04-18.