The Upside Down Triangle

Saturday sunshine spilled across the nursery floor like warm butter. Grace sat on the rug in her stripy socks and hummed a little tune. It went up and down, up and down, like a cat on a fence.

Then something in the toy box hummed back. It was a squeaky, honky sort of hum. Grace stopped and peeped over the edge of the box.

A small red fire engine rolled out and bumped into her knee. He had a silver ladder, a shiny bell and a very worried face.

"Hello," he said. "I am Freddie the Fire Engine, and I have a problem."

Grace giggled because the fire engine had just talked. She picked him up and set him gently on the rug.

"What sort of problem?" asked Grace.

Freddie rang his little bell sadly. "I want to build a fire station," he said. "But I do not know my shapes. I need a square for the wall, a triangle for the roof and a circle for the window."

Grace tipped out the box of wooden blocks with a big clatter. Blocks tumbled everywhere, red and blue and yellow. One rolled under the bed and one landed in Freddie's ladder.

Freddie zoomed off and came back pushing a round yellow block. "This is a triangle," he said proudly. "It is perfect for the roof."

Grace turned the yellow block in her fingers and felt all around its edge. It was smooth all the way round, with no bumps at all.

"This is a circle," said Grace. "A circle has no corners at all. Feel it, Freddie."

Freddie rubbed his bumper along the block. "Oh, it tickles," he said, and he laughed so hard his bell went ding.

So the circle went in the window spot. Now Freddie needed a roof. He rolled and rolled across the rug and came back with a blue block.

"Is this the one?" asked Freddie.

Grace held the blue block up and counted its corners with one finger. One, two, three, four. That was too many corners for a roof.

"Not that one," said Grace. "But it is just right for the wall."

She ran her finger along each side, slowly and carefully. All four sides were the same length, and every corner was square, like the corner of a book.

"A square has four sides of equal length and four square corners," said Grace. "This is our square."

Freddie was so happy that he spun in a circle. Then he spun the other way, got dizzy and tipped gently onto his side. Grace laughed and set him back on his wheels.

"I am fine," said Freddie. "I was only checking the ceiling."

Grace put the square down first, nice and flat. It made a good strong wall. The circle sat beside it as a round window.

Now only the roof was left. Freddie dashed under the bed and came out with a fluffy grey sock on his ladder.

"Is this the one?" asked Freddie.

Grace laughed so much she had to hold her tummy. "That is my sock!" she said. "Socks do not have corners. It is floppy, Freddie."

Freddie looked at the sock very closely. "It is a very good sock," he said. "But it is a very bad roof." He dropped it on Grace's toes.

Grace looked through the pile of blocks herself this time. She found a red block with pointy ends and counted its sides. One, two, three. Then she counted its corners. One, two, three.

"A triangle has three sides and three corners," said Grace. "This will be the roof."

But when she put it down, it landed on its point. It wobbled like a spinning top and leaned to one side.

Freddie gasped and backed away. "That is a new shape!" he cried. "That is a pointy-down shape! Is this the one?"

Grace hummed her little tune so she would not get muddled. She counted again, very slowly. Still three sides and still three corners.

"It is still a triangle," said Grace. "It is only upside down. Turning it does not change it."

She turned the triangle around until its flat side sat on top of the square. Now it looked just like a roof, pointing up at the sky.

Freddie stared at the roof, then at Grace, then at the roof again. "Well," he said. "The triangle was only standing on its head."

The fire station stood on the rug, square wall, round window and triangle roof. Freddie rolled up beside it and rang his bell three times.

Grace picked up the sock and counted its corners just for fun. There were none, of course. She put it back on her foot.

"Thank you for my fire station," said Freddie. "Have a lovely day, Grace!"

Grace waved and went to find her other sock.