Mathness!Math Worksheets
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Finding a missing angle when a bigger angle is split into parts, knowing a straight line is 180° and a square corner is 90°.
Make a sheetDownload PDFThe PDF has this sheet, its answer key and a guide for grown-ups.
The parts add up to the whole angle. Take the part you know away from the whole: 90° − 35° = 55°. Check by adding the parts back together.
Watch for: Using 90° when the parts sit on a straight line (180°). Adding the parts when the whole is known and a part is missing. A subtraction slip that adding the parts back would catch.
At home: Fold a paper corner (90°) and draw a line out from it. Measure one part, then ask your child to work out the other.
Luna's Space Adventure
Grade 4 · Missing angles · 4.MD.C.7
Astronaut Luna is exploring a far-off corner of space. Solve each problem to help Luna's mission go smoothly!
A straight line is 180°. A square corner is 90°.
The two parts make the whole angle.
Luna's Space Adventure
Grade 4 · Missing angles · 4.MD.C.7
Astronaut Luna is exploring a far-off corner of space. Solve each problem to help Luna's mission go smoothly!
A straight line is 180°. A square corner is 90°.
The two parts make the whole angle.
New problems every time, three levels (gentle, core and stretch), themes to pick from, a second page if you want one. Each sheet comes with an answer key and a one-page guide for grown-ups.
Save to PinterestCommon Core 4.MD.C.7 · Find missing angles by adding and subtracting.
Also: Maryland 2025 4.GR.B.7 · Texas TEKS 4.7E · Florida B.E.S.T. MA.4.GR.1.3 · Virginia SOL 5.MG.3