The British 50 pence coin has seven sides.
It is a rounded heptagon.
Each curved section follows an arc traced from the opposite point on the coin, so its curvature is twice that of a similar-sized round coin. However, that also means that its diameter is constant at any orientation despite being multi-sided, which allows the coins to move freely in vending and counting machines.
Seven
The British 20 pence coin has seven sides.
It is a rounded heptagon.
See related link for a picture.
The British nickel-brass Threepence minted from 1937 to 1967 has 2 sides, but it has 12 edges (dodecagonal).
The British brass Threepence issued from 1937 to 1967 inclusive has 12 sides.
5
A British twenty pence coin has seven sides.
There are 50 British Pence in a British 50p coin.
8
The term "New Pence" ceased to be used on British coins in 1981. The word "Pence" should have a numeral with it to indicate how many Pence. Pence being the plural of Penny. In 1997 there would have been 50 Pence, 20 Pence, 10 Pence, 5 Pence and 2 Pence coins and a 1 Penny coin.
There are no "grooves" on a British 1 Penny coin. The edge is not milled.
A two pence coin has a diameter of 2.59centimeters.
130 British Pence is equal to One Pound and 30 Pence.
It has 7 sides but they are not flat, they are slightly curved. The coin is designed to have a constant diameter so that vending machines work with it.
The British 2 Pence coin weighs 7.12 grams, so 100 of them would weigh 712 grams.
The lion has been a British symbol for many years and is symbolic of British strength and courage, and royalty, since the lion is known as the king of the beasts. The lion on the 10 Pence coin is described as being "passant guardant" (right paw raised with all others on the ground).
Your description is applicable to every British coin issued in 1979. On the same side of the coin you read "New Pence", there will be a number indicating "how many" New Pence. The 1979 British 1/2, 5, 10 and 50 New Pence coins have long been withdrawn from circulation and have little or no value unless they are in mint condition, and even then, not much. The 1979 British 1 New Penny and 2 New Pence coins are still potentially in circulation, so are worth 1 and 2 Pence respectively, unless they are in mint condition, and even then, not much.
As at May 2013, the British general circulation coinage consists of - 1 Penny 2 Pence 5 Pence 10 Pence 20 Pence 50 Pence 1 Pound 2 Pound coins. The Five Pound (Crown) coin is legal tender, but is not widely accepted due to its unfamiliarity.